Ambien losing it's effectiveness

Hi, I just stumbled across this board in a google search because I was looking for help. I have had insomnia since I was 14 (I''m 20 now) I started Zolpidem (Ambien) this summer and it''s worked great. I''ve read things that say you should only take it for 7-10 days but the doctor kept giving me refills and as long as it was working I kept taking them. Within the last week the pills have become less and less effective. I take the 10mg and get into bed as I usually do, and I can feel when it kicks in. At that point where I would usually drift off easily to sleep, I''ve started fighting to fall asleep again. After about ten minutes of feeling the "buzz" it wears off and I feel like I didn''t even take the pill, putting me back at square one.

I try to stay away from using it on the weekends and days when I don''t have to wake up for anything to avoid a tolerance being built up. But I''ve had to use it for the past 2-3 weeks straight, without a night off. Could that be what''s causing it? I just don''t know and I''m worried because it''s the only way I can sleep at this point and as we all know... sleep''s kinda important.

Any help is appreciated thanks alot.