Dextroamphetamine sulfate symptoms and conditions

I've been taking Adderall XR 30mg per day for two years. I've gained 20 pounds and feel terrible. My doctor keeps telling me he doesn't know why I'm gaining weight. That is making me feel even worse!!! Can anyone tell me what's going on??? I also take Wellburtin & Lexapro. Before I took any of these medications, I asked the doctor if I could gain weight from them. He told me that these particular drugs do not cause weight gain. The thing that's so frustrating is, I was put on these drugs for anxiety and depression (results of an abusive marriage). How can I begin to feel better about myself if I'm gaining lots of weight? That just kills it for me. Can anyone out there offer some advice? My doctor won't even let me take an appetite suppressant. I take Adderall in the A.M. If I want, I can go right back to bed and sleep again. I also get hunger pains about 2 hours later!!! Help!!