OP you remind me a lot of my younger self so I will give you some advice that I wish I had heard.
When I started grad school I was kind of young (20 years old) and it was one of the first times that I had to live by myself. I had little interaction with the academic department, no roommates or dormmates, my gf was back at my undergrad university, and I went from playing D1 soccer in undergrad to not having any organized sports activities. I also had (and still have) an addiction to the internet, and because I felt so alone in grad school I turned to the internet for primary social interaction. I think what made this situation even more difficult was the idealistic expectations that I put on myself. I wanted to basically have 100 percent efficiency with my time; i.e. be on a rigid schedule and only have down time during scheduled times at night. I wanted to be the perfect person and live an honorable an ascetic life to the best of my abilities. For me this meant I wanted to play pro soccer and be the best mathematician I could be. When I would waste time on the internet, it would feed into this self loathing cycle and I would try to be even more regimented. That would last for a few days, and then the process would repeat itself. My studies were not going great (went from undergrad 3.95 GPA to 3.48 first semester) mostly because I was in a new environment and needed time to adjust, but I instead blamed it on my time wasting, which was nonetheless admittedly bad.
My second year, I started growing out of wasting so much time on the computer and I settled into a really fantastic schedule. I would get up at 6:45, go to the dining hall at 7:00 for breakfast, and go straight into a lift. I would go between classes and the library all afternoon, either play pickup soccer or train on my own before dinner, and then come back to the apartment around 8:00-8:30. It took me a while to find my groove, but once I did I really felt great, like I had an entire semester where I thought I was living to the best of my ability with nothing else to get in the way. I still don't really know why this semester worked out so well, but being out and about for most of the day helps a lot personally.
Now from the looks of it, it seems like you have two issues here. I will address these separately.
(1) You want to live an optimal lifestyle, challenge yourself, or some variant of being the best you can be. Personally, living out of a car would be too much for me but I understand the emotion behind it. From personal experience sleeping in a RAV4 once every couple of days, it sucks. The car is not as insulated from the weather as you might think. In the winter you'll need blankets and pillows, and in the summer if it's to hot you're basically trying to sleep in an oven if you keep the windows up and that can kill people. With the windows down you're dealing with bugs, noise, weather, etc. If you're looking to park the car somewhere, I have slept in hotel parking lots with other cars around. But really you're selling yourself short by sleeping in a car, particularly because unless you have experience there's no way you can optimally sleep in such an environment, and sleep is so important for whatever else you are trying to do. In my opinion, you should get an apartment without internet/cable/tv, and ditch the smartphone. This helped me immensely, and not having a phone to connect to the internet (I used an LG Cosmos 3) was great so that I could eat meals without being tempted to waste time online. One other thing that I liked was only using the internet when there were other people around, like in a library. I had an office for my first year of grad school and it sucked; the space was cramped and I always wasted time when I was there. Later, I used to go to the library and use peer pressure from other people there to do work. Also, and this was the key for me, try to start your days as efficiently as possible. For me, this meant waking up, putting on clothes, gathering my stuff, and getting out the door in 15 minutes. The longer you stay inside and isolated, the more likely you are to slip into bad habits and waste time. If you can at least start your day right, you are one step closer to doing your best work. Regular bedtimes are a must, even if you drop hours of sleep like me because of insomnia. In the long run having a regimented sleep schedule (even on weekends) will help.
(2) The promise of living an efficient/ascetic lifestyle is not sustainable in the long run and can be incompatible with the spontanaeity of life. I didn't realize that what I was trying to emulate was an OCD fantasy. Yes I had a great time when I was living the life of a monk-athlete, but you can get carried away with it and miss a lot of joys in life by being so regimented. For instance, my behaviors started to filter down to my diet, and I would be really uncomfortable in situations where healthy foods were not available (i.e. going to friends houses, or being on travel). I would constantly be angry at myself for not sticking to a schedule and it really caused my a lot of avoidable anguish. When spending time with my gf I would feel guilty that I wasn't studying, and I think that made me realize that someday I was going to have to give this fantasy up. For example, when and if you have kids, you shouldn't have to fit them around your optimized life. Over the next few years I really took a step back and re-evaluated my priorities. I started to be less hard on myself for going on the internet, and I started training less. Because I was overtraining then, I train half as much now and I am definitely in better shape than I was. My life with my wife is more fulfilling because I have relaxed about my diet, training, and productivity and I can just enjoy our time together. The irony is that now I probably have a more scheduled life now than I did, but it doesn't feel that way.
In conclusion, I encourage you to try to live your best life. If you think you can live in a car like a monk for a while, by all means go for it; I think it's great. However, you should put some thought into why you procrastinate and try to accept yourself. It really is okay to be a naturally lazy person when no one is watching, just put yourself in situations where it will be hard to go on the internet unsupervised. Nothing wrong with that. I just can sense some of the same self loathing in you that I had in myself, and I just wish someone would have told me that I could be an accomplished person and not put myself through a trial to get there.