So sorry you're feeling so low @raspberrylime123, it really is awful.
I don't think that "stop obsessing and worrying" is helpful advice - if someone had a health concern nobody would tell them to stop worrying about it. It feeds into the idea that you're doing something to stop yourself from getting pregnant which you're not.
Good suggestion from @VenusStarr about counselling. I haven't had proper one-on-one counselling but did manage to get a 5 week group CBT course through a local service that my GP recommended which helped a little. Could you look into local services or speak to your GP?
Also, I've found that I find it a little less difficult now that I have a plan in place - have you had any fertility investigations? If you've been trying over a year (or 6 months if you're over 35) you can speak to your GP about it and they'll likely arrange some blood tests to check you're ovulating and poss a sperm test for your partner. It's a good first step.
I'm sure you've already thought of this too but is there anything you can do to help relax? Colouring books, knitting, reading, massage, walking... any hobbies that give you a little "you" time to try and switch your brain off? Knitting and acupuncture have helped me in that respect.
Good luck and hope you find yourself feeling better (and preferably pregnant!) soon xx