Self-improvement should at the end of the day mean improving your life , making yourself a happier person (in the hedonistic sense) , this includes stuff like delayed gratification ofcourse.
If you dont want to have a social life its ok , if you do , thats ok as well. I personally just dont feel the need , considering you mentioned it you likely do. Do not be influenced by what others think of you (for example: "I must have [X] because soceity will thing bad of me if i dont")
Think about it , is it a genuine need to connect with other human beings (or something along those lines) or is it just "soceity will (not) like this" (do this for basically everything for example , nice cars, nice clothes, latest iphone , etc.) .If you do , i cant help you. The pandemic likely made it harder , and try finding people with similar intrests but thats about all i know.
WARNING: DONT fall into the trap of trying to delude yourself into thinking you dont want a social life when you acttualy do because its too dificult.
Having a hobby is nice , everyone should have an activity that brings them happiness , idk how you go about finding one.
I have hobbies but i burn out on them eazily (drawing and programming sometimes) , i guess one piece of advice whould be to not do them obsessively untill they no longer bring you happiness (burn-out).
Idk , try this, make a notepad file , go thought this list (https://en.wikipedia.org/wiki/List_of_hobbies
) and write in the notepad all the ones you find intresting (for example: Drawing , Gardening , Pyrography, Computer programming) , then rank them in order (example: Programming , Drawing , Pyrography , Gardening) and go thought them in order of most intresting to least and tell me if it worked. ok? if you find one good , and keep looking , espeically if burn out is something that happens a lot so you can cycle thought them (ie. Burned out on drawing? do comp sci? burned out on comp sci? do pyrograhpy? , burned out on gardening? hopefully the burnout on one of your hobbies has lifted off and you can do it again.
(youtube tutorials could help you get started)
I still need help with mentaining my hobbies and in terms of "how i found them" , idk i just found a thing in my YT recommended section and just decided "gonna learn this why not". If anyone has more info on this stuff feel free to give additional adivce.
I am 100% this happened for programming , i remember the 4 hour or however long python programming course ( this one: https://www.youtube.com/watch?v=rfscVS0vtbw
) , dont know what got me into art tho.