You have a sedentary lifestyle with a sedentary job. Your 25 and been out of school, I'd guess for 3 years. I am guessing that you haven't been physically active since high school - 7 years (bare with me, I'm trying to make a point). You said you are weak. You have only been lifting for 1.5 months. You admit you have bad form. Does all this sound fairly accurate at this point?
To cut to the chase, drop weight you are lifting and learn to squat properly. You have all these ligaments and tendons and muscles that you haven't used probably since your high school PE class. You living a sedentary lifestyle probably has you all stoved up. You need to learn to squat properly to get the flexibility you have lost and start building all the little stuff needed in the squat. I believe that if you start doing this and don't let your ego get in the way, you'll start to see some progress.
The thing about box squats is, you don't have to sit on the box. It really isn't a box squat at that point, but the box under your butt does a couple things:
Keeps your depth consistent
Teaches you how to sit back, because you won't ever fall to your doom all the way to the floor. You can shift your weight back and grease the grove with the "safety net" of having the box to sit on if you fail
Here is my front squat, I have this under my butt anytime I squat. Never sit on it unless I fail, but I always "squat to a box". But I don't ever deload on the box, just tap it with my cheeks and stand up.http://www.youtube.com/watch?v=Ew7EWaBlPa0
(Hanging chains from the bar will teach you to balance very very quickly, but that is light years ahead of you at this point, so don't go crazy here. I'm showing you how I use a box, lol.)
Why don't you try front squats?
T-nation has recently posted an article about it: http://www.t-nation.com/free_online_article/most_recent/front_squats_made_easier
If he is falling forward as is, I don't know that front squats are the best idea. He will be eating floor in no time, lol. ;)