There are many fantastic high-potency strains that you could most definitely benefit from. I am so glad that this question came across my screen today, especially since I have some knowledge of Serotonin.
Serotonin is such an extreme tranquilizer/mood-stanbilizer that going through withdrawls is a REAL issue. Serotonin hits you hard and holds you under for hours up hours. Recovering from that rollercoaster, especially if you have been on cycles for quite some time, can be very difficult.
It will be extremely important to consult you physician to blueprint your exit strategy from the pills. This would also be a great time to consult your doctor about the cannabis regime that you plan on using to help combat the effects of the previous medication.
I would recommend a strong Indica Dominant/Hybrid straing. Perhaps something like Skywalker OG or OG Kush. These flowers pack a punch that could help to balance out the nasty effects that you would be feeling from coming off of the pills.
It also may not be the worst idea to mix some good cbd dosages in there as well. The aches and pains that come from withdraws can take a toll on you. This can help to alleviate the pain even more.
As with most things that are natural and individualized, start slowly. Listen to your body. Best of luck
davidgoad