Why can't I get high anymore?

I started smoking weed 10 months ago and used to get so f*cking high it was ridiculous. It could be cheap bud, shake or whatever. I'd have amazing highs for a good few hours. Now, even when I smoke dank bud (ak47, black widow and sh*t like that), I don't even get that high anymore. Sometimes I get lazy, relaxed, and hungry and like listening to music but it's just not the same. I don't feel the universe taking off anymore, just a boring dull feeling in the back of my mind. I want to get high so bad. Can't afford my own bud but I get supposedly good strains from my bf. I know I built up a tolerance. Do I just smoke a bunch more? I have a cough with wheezing right now so I'm taking it easy with the toking. Once I get better what should I do?