Anyone who's done insanity-- some advice please!

Hi so I'm on week 3 of insanity. I have gained 1 pound (of muscle I'm guessing) and I think my waist looks slightly tighter. I'd like to know from people how much progress they had after week 6 of insanity-- week 1 of month 2. Unfortunately, I am going back to college after that so I won't have the space, time, or food required for insanity work outs. I'll keep working out of course, but I'd like to reach my fitness goals by then, and then maintain them afterwards! Everyone says month 2 is where they've seen huge results, but are there decent results after the first week of month 2?

Some more advice-- would anyone suggest doing extra work outs like running while doing insanity? Or would that be too much? Also, I am 5'3", 115 pounds, and eating 1500-1600 calories a day. I'm afraid to increase or decrease this amount because I don't want to eat too much but have heard that if you decrease too much, you won't lose weight.

Thanks for all your help!