Ok, I'm not an Aspie, but I have struggled with mood issues and obsessions for most of my life. I've found that the medication that works BEST for putting me in a positive state of mind (without going overboard, into mania), are those produced naturally by the body as a result of any kind of endurance training: walking, running, hiking, etc.
Sorry, I know this doesn't answer your question, but if you're not fit and don't regularly engage in some endurance related activity, I would encourage you to go our for, say, an 1/2 walk each morning and see if that doesn't put a dent in thing. The hardest part is starting.
I agree, meds should be a last resort.