I can totally understand following through with those things being difficult because depression is a self-reinforcing cycle that's symptoms really mess up your perception of the world. I think you're right that people choose hobbies because they enjoy the thing they're doing. Sometimes because they're competitive personalities. You don't have to necessarily cure yourself of anhedonia to choose, if you can think back to how you were before depression did you used to like doing certain things? It could be a start. I also have seen that some people's desire to find the perfect answer on the first try makes them think too much and do too little, for situations where thinking can be paralyzing, the best way to know is to try.
For your drug question: I'm not a pharmacist, just a hobbyist with a background. There's quite a few theories on how serotonin improves depression, and one of them being that it increases neuroplasticity so that your brain can form new connections and escape bad ones, and another that it stabilizes mood to stop you from feeling lows of sadness as strongly. Those are the two main theories that I know. There are more, but I don't know all of them. Just the main ones. I don't think serotonergic drugs would help you as much. HOWEVER, serotonergic drugs aren't the only antidepressants :) there's also drugs that act on norepinephrine, which gives you more energy and better concentration. The increased energy could possibly give you more energy to try new things and help you out. So look into NDRIs, NRIs, and SNRIs (ignore venlafaxine and desvenlafaxine as they're very weak norepinephrine actors and mainly SSRI). The thing drug class consideration you could make is dopaminergic drugs, but I don't have much to say about that bc they're rare to come by. I think they could help you out though! Tl;dr it depends which one, but yes it can help
Also, I'm curious what happened when it came to socializing?
