Welcome to self help!

For all those things; depression, anxiety, feelings of worthlessness you have started doing the best thing. - something! Do something! Some sort of action rarely makes you feel worse, and asking for help is a large piece of positive action.
Pessimism and inactivity will make you feel worse.

Start small; change isn't easy, it will be stressful - you have to take comfort in that! And consider that it will be a life-long habit. - however, don't be put off by that, one step at a time. I like to give myself five minutes at a time. you can always do more, but you never overface yourself.

may I suggest Psychological Self-Help
by Dr. Clayton E. Tucker-Ladd

It's available free online, it doesn't push any singular treatment method, but it does give a sensible framework to organise yourself for the work ahead.

Best wishes & good luck