It's doable, but it means a good deal of work and time- depending on how out of shape you are now, it might take a couple of years to get back there. I'd say be patient building your base back up for several months at least. When you get back to doing speed work, try and keep a realistic idea of where your fitness is now- don't try to kill it based on how fast you used to be or how fast you want to be and get yourself injured. I would recommend keeping a detailed training log to track how your paces get better over time. Hey, if you start out slow, that'll just give you that much more room to improve.
If it gets too frustrating, I'd also suggest you can try moving up in distance- if you're consistent about running year round in a way you weren't as a high schooler or college freshman, you could easily run a 10K that would put your teenage self to shame.