Buspar will work great. It's supposed to be a 5HT1a partial agonist. It is supposed to help with anxiety. It's better known by most as a sugar pill! Basically a very weak drug often called a placebo mint.
Lexapro at 5 mg for depression. 10 mg is the regular dose. Though some go up to 20. The best thing about Lexapro is it is the cleanest SSRI. It has been shown for the majority to have the least side effects of all SSRI's and you don't have to really play to much with the dose. But you were taking a NDRI in Wellbutrin. No 5HT- serotonin action or very small.
I just read some of the other part of the OP. 25 mg of Adderall for 12 yrs without breaks? I can almost guarantee dependence and probably the main issue for your mental state. It has the l and d isomers. So ,Adderall can tend to cause more anxious feelings then dextroamphetamine. Here is a good article on it:
http://www.hightimes.com/read/addera...te-amphetamine
Yeah , it's from high times but it explains how the medication functions well.

Basically it's draining your neurons and cell production of dopamine and norepinephrine over this period of time. Your DA and NE receptors are probably severely down regulated and depleted. You need to talk to your doc or hopefully pdoc about this. Prescribing that dose for 12 yrs. is verging on malpractice unless you have severe ADD or ADHD. Also is it the regular or XR type? You really need to talk to your doc/pdoc about this.