Does Combination Of Adderall, Wellbutrin And Lexapro Treat Major Depressive Disorder?

I was put on Adderall in Sept.2013 since I have always had the Major Depressive Disorder(DSM) I have tried ALL the anti depression medications on the market with the last one(s) being 300 mg Wellbutrin and 20 mg Prozac. I stopped both of these when I started taking Adderall 10 mg twice daily. Wow, did it make a difference. I was so much more motivated and focused on getting work done, up until late December when I no longer had that boost of energy. I saw my doctor again this month (February) and he added on Lexapro 10mg once daily with 30 mg of Adderall(15mg morning, 15 mg early afternoon). As of date, I have not noticed any change and feel like doing nothing but lay down and rest/sleep. I would like to try and go on Wellbutrin again. Do you think that 300mg Wellbutrin once daily, 20 mg Adderall twice daily, and Lexapro 10 mg once daily would be a safe and working combination? Also, what time daily should I take the medication? I am going to speak to my doctor about this also but wanted to see what your recommendation would be? Thanks, Richard