I can relate to what you have written (solved now because of medicine). You have barely any motivation, you don't really want to learn new games because it takes "effort", you don't really want to do all the side quests of a videogame because the mainquest is where the most fun is and you probably see everything fun like videogames and movies as "work, work, work" or "effort, effort, effort". But what you can do is search for mods, over and over and over. You want the next best thing that will probably make your game AWESOME! It's like going through a catalogue of free items, and you just feel happy clicking on the next thing hoping to find another item that you really want. And when you actually play the game, you don't really feel that happy or hyped up as you were finding/installing those mods...
In my situation, the reason why I was able to focus so much on finding/installing mods was because of dopamine. Each time you find a new mod, you get a dopamine feeling and want to know more/find more and make your game more awesome then EVER BEFORE so you can FINALLY ENJOY GAMINGGGGGGG!
But that is a lie. And I now know why I did that (and all the other countless of ADHD things). I went to the psychiatrist and they explained how my brain worked. You see, a brain has a normal process of "creating" dopamine and "consuming" dopamine. This is a perfectly normal cyclus within everyones brain to ensure proper brain functionality. But in my brain, the dopamine system creates dopamine normally but the consuming of dopamine goes waaaaaay too fast. This causes a dopamine deficiency and is the main cause for my ADHD symptoms.
My dopamine deficiency caused me to try find the best new thing, or only want to do the most fun and easy stuff and not the stuff that requires even a spliner of effort because I had to keep my dopamine levels high in order to be happy or enjoy stuff. This all happens kind of sub-conciously. But now, I take medicine in order to fix that problem. My psychiatrist gave me "Methylfenidaat", about 40mg a day right now. What that does it lowers the consuming of dopamine within my brain. My brain creates dopamine, but now with a lowered consuming of dopamine because of my medicine, I now no longer have a shortage of dopamine in my brain but a constant balanced dopamine level.
Right now, I no longer have any of these problems. I enjoy everything, I don't even want to play videogames sometimes anymore. I just prefer to sit at a bench and think about life or the future and find more joy in those thoughts then playing games. I can now read books and watch movies, even in a very slow pace. I don't necessarely feel "happy" but more "content". Everything is fine and everything is under control. Life is beautiful now, no more depression, no more self hathred, no more anger or constant irritation. Just peace of mind and focus, and I can actually enjoy just looking at the sky or seeing people walking by.
This is kind of my story and this may not be the same for you. Every brain is SOOOOO different and SOOOO unique, but I had it really rough and have finally found the solution. I would always recommend everyone to find a psychiatrist, to keep fighting for a diagnose or for an appointment. I hope you will find the solution like I did and maybe another medicine is better for you or perhaps maybe something else (technology grows insane, I wouldn't be surprised if there are new solutions out there). Maybe things will even go better for you then for me. I hoped this gave you a little bit of an insight or maybe a little bit of hope.