Since you're not smoking tobacco cigarettes you're actually much better off. Plain weed (I'll assume) has little to no (depending where you're buying it) additives, and if it does they're not very harmful, so you're not going to have permanent amounts of tar stuck in your lungs like you would from cigarettes.
This will be something you'll be able to bounce back from, probably just as good as before, but it will take a while. Your lungs are screwed up, but not permanently.
