Advice Needed

What I do personally to help me with motivation and productivity is to set smaller goals to accomplish and to them more often.
For digital art I did a one art a day kind of thing, where I really limited myself to avoid "feature creep". Used 16*16 pixel canvases with limited colors where is was not allowed to add new, that way you force yourself to focus on bringing the best out of what you have, and i also limited time to max an hour, so i can fit it into my afternoon instead of random youtube videos/stream watching/gaming. Altough I do not advise strictly daily things, it did help me immensly.
Atm I do the same with hobby coding. I look at a feature, for ex. adding a new power-up where you can shoot fireball and take it step-by-step. One day create the art and the ingame object. On another create the state and the logic for the shooting. Next I do collision. After that maybe some polish with particles and sounds.
Breaking down things into smaller easier steps helps you feel motivated, to stay in the "I can do this! I did this!" and not get stuck focusing on the bigger picture. What happens if people won't even like this power up? Who cares now, I'll deal it when time comes to it.

With depression I cannot really give you any real advice, as I'm not qualified to do it. If you can, please seek out professional help, that is basically your best option. If that is not really available for you I'd try to surround myself with my friends and things I know I enjoy. Go out, have a chat with your friends, if you don't really have any try to reach out in the communities of your hobbies you enjoy! Physical activity also helps, go for some morning walks, try to build up a routine that helps you relax.