Is my relationship salvageable or should we give up?

I've been with my boyfriend for over 2 yrs, and the whole time he's accused me of "being slick" even when I never had "slick intentions." Until a month ago when I cheated. I knew he was doing something behind my back for weeks but after I cheated I found out he had been doing drugs behind my back for months not cheating like I thought. We have terrible communication skills but still want to try to work things out. The only problem is he's started a new job and is focused on making a name for himself so he can't focus on our relationship right now. How long do I wait for him to have time for us? Or should we just quit now?