i was in a similar place to you not so long ago! it changed around so quick!
that is why it is worth holding on, with the right help you can get through anything!
have you tried to seek help for the way you are feeling?
also try to think back to when you were happy, if you can, and try to think of anything that may have affected your mood in anyway! no matter how small! then you may be able to focus and work on the root cause of your problem!
honestly, the journey isnt nice, but its sure worth it at the end! just think how much stronger you will be once you are through it!
is there anything you do that makes you happy, if only for a little while or the time you are doing it?
also if you find yourself getting more agitated or down, try to take some time out, close your eyes and focus on your breathing, think about the sensations you get from that! and when you feel relaxed start letting thoughts enter your head, if it gets too much, then just focus on the breathing again!
may sound silly, but it really does help!
hope this helped! and would love to hear back from you! take care! x