Why does Adderall make me feel like this?

I was diagnosed with ADHD and started with 7mg of Concerta, working my way up to 54mg. It was alright but I realized that it was making me feel very very depressed, very anxious/jittery, and it kept me awake at night. I told my doctor and she suggested I go on a lower dose or try a different medication. I chose to try a different medication and she prescribed me Adderall. It started of fine I didn't feel weird or depressed but it also wasn't doing much for me as far as keeping me focused at school. I went up to 30 mg about 3 months ago. I am doing amazing in school and I am also in the mood to write, read, study, or anything to keep me busy! The only problem is that now I feel very strange. I am always in a negative, glum, mood. My friends invite me places and even if I normally would love to go, I still say no because I just don't feel like it. Nothing sounds fun anymore! I feel like a robot. All I want to do is do school work and it's not even that I want to, I feel like I have to. It's so hard to explain. And even when I'm doing something I'm interested in, or enjoy, I still feel "blah" or just in a bad mood. When I told my doctor, she prescribed me Lexapro 20 mg. That has helped slightly, but not as much as I'd like. What can I do to help this? I don't want to be like this but I don't want to stop taking it and ruin my grades. I'm a 16 year old girl by the way. Please help me! :(