Recommend you lose that weight. Get an app like MyFitnessPal or really any weight loss app. Set it to make sure you lose about 1 lbs a week (or a 500 kcal deficit per day). You will likely feel slightly more tired on hard days and not quite as able to keep up the pace. When I am losing weight and trying to train, I often set my workout paces to be slightly slower than usual and do shorter repeats. For example, If i might usually do a 6 mi tempo @ 5:30 / mile, I will do 4 or 5 @ 5:40 / mile. The effort will be there and so long as I do a few 100 - 200 m reps, I find I maintain my speed. I also may do fartlek instead of hard sessions.
I also recommend running some short hill repeats to keep that leg strength. I guarantee that if you lose the weight and keep the muscle, you will find yourself running ~1.55 within a few races.
A few tips - keep lots of fruit around like apples and berries. I find that these can both keep me full and keep me from eating crap. Pick up a protein powder. I don't necessarily need the extra protein but ~100 kcal of PRO can keep me feeling fuller, longer. Drink lots of water. Run hard. I find that running hard both speeds the rate at which I lose weight, increases the amount of that weight that is fat and blunts my appetite. Getting in the weight room for light sessions has also helped me during these periods of weight loss. Finally, if you're not a black coffee drinker, become one. I find that a good cup of coffee give me more energy to get through workouts, blunts appetite and keeps me lean and away from the sweet beverages. It is also something to keep your mind off of eating. I think the other thing that can be helpful is running twice per day. When i'm losing weight, I often feel bad at the start of runs, good to great in the middle and then fatigue at the end as I begin to crash. Therefore, I try to do two shorter runs instead of one whenever possible. I double most days as it is but when I'm eating full kcals, I can easily do a double like 4 mi / 11 mi or something. When I'm fatigued from a caloric deficit, I find that 6 mi / 9 mi or 7 mi / 8 mi goes a long way towards getting me to the key sessions feeling good.
Finally, I often give myself a day to "cheat" every couple weeks. Often the day before a key session, a good LR or a hard track sesh, I will eat an extra 1000 kcal the day before. In the process i "lose" two days but find that if i don't do this I will go crazy.
Anyways, the short of it is that you're slower because you're a lot heavier. Keep the muscle, shed the fat and train intelligently in the intermediate and you'll be running fast in no time.