I'm sorry to hear that you feel that way. It sounds like you're on a horrible rollercoaster of emotions recently. I've been in that position, so definitely relate to how you feel. Something that helped me was choosing something that I wanted to get better - you mention that you want "things" to get better, so choosing one of those "things" in your example. For me, it was improving my physical health, and setting goals really helped me to direct my effort at the time and focus on something other than the emotional rollercoaster.
I know it can be difficult to put your mind to something when you're feeling like this, but just a suggestion that worked for me and a few others I know. I hope you feel better soon - here to support you through thisx
Much love <3