I dont have an answer on drug interactions, but if this were me I would concentrate on one issue at a time. If you try to tackle everything, you just might not succeed at anything. Pick your main problem and work on that with all you got. I read somewhere that 90% Seratonin is synthesized in the gut, so it might make sense to start there. Having said that, you have to get worse to get better and those emotional problems are going to feel very big for a while. But when you find yourself bawling your eyes out know that it's not you, its just your body detoxing (I had a good bawl today, felt so much better).
I would call the people who sell Threelac and ask them about interactions with other meds.