I need advice for diy-ing my old fast fashion hoodies , jeans and skirts as a plus size alt girl

I usually consider myself eco conscious but I never realized that a lot of my clothes might actually be fast fashion especially “No boundaries “ which is a Walmart brand I believe and as a plus size college student obviously my budget is pretty low. I’m trying to have a more alternate clothing style and i would feel very guilty to just throw this stuff or just reset my closet entirely…is there any way I can manage and fix these? I’m trying to also make them more durable.