I wanted to start by asking in addition to the antidepressants, what professional support are you getting for depression? It may be that you need to review your medications, but do you also feel that it would be worthwhile getting some help with the loss of your baby and the loss of your relationship?
I'm guessing that your self esteem has taken a bit of a beating, so it may be worth working on this before trying to seek a new relationship. People will leave us, and some people may not like us, but if we are confident within ourselves we won't always be blaming ourselves when things don't go as we planned. This is something you could work through with a Psychologist, or you may like to find a support/therapy group you can join.
I'm glad to see you have tried platforms like internet dating. I wanted to share the story of how I met my partner. I was 29 and had just ended an emotionally abusive 10 year relationship. I really started to feel like I'd never meet anyone and that I was destined to be alone and without a much wanted family. I decided to try online dating, and it was here I met my partner. We have been together almost 5 years, and are now in the family planning stage. I hope to give you some hope, it's not too late, you will meet someone who truly deserves you. The benefit in having some failed relationships is that you really begin to know what you don't want from a partner. Try to look for Mr right now, rather than Mr right, and just have fun doing so.
Have you tried meeting people in other ways? Perhaps focusing on you for a little while. Join a sports club, start a hobby or join a group. Maybe even get your friends on board with setting you up. Friends seem to love doing this, and again it can be a bit of fun.
I hope you will post again.