Help!!

I gave birth to my son at the beginning of June, I breastfed him for two weeks, but was not successful so I stopped and switched to formula. He's almost two months and since I hadn't dried up yet i decided to try to breast feed him again, it's been about a week and I'm still having to supplement. Any mommas have ant experience doing this? I really wanna breast feed... My milk seems to be coming in slowly again, to fit his needs, but I'm not able to pump because it hurts and nothing comes out. I wanna up my supply.. Any advice?