Love is something you are, and something that you share. The fact that you want to shed the "hard" layers that prevent you from feeling/doing each can help you get there if you want it. I hope you can find a way to get into therapy if that's something you feel would be helpful (I saw your comment on it being difficult in your locale).

A few, simple things you can try, right now: Make a list of what you're thankful for. It might be small, and maybe today you'll only seem thankful for one or two things... but do that every day. Perhaps today you're thankful for having had a good man whose presence in your life brought you to a place where you want to improve yourself, even if you didn't get to keep him?

Meditating is good. Any time you start beating yourself up; stop and breathe. Honestly extreme self-criticism can be a tool of procrastination, or something we use to "prove" to ourselves that we can't accomplish something. You won't learn to treat others well by mistreating yourself; practice setting expectations of yourself which facilitate respect for yourself and others.

Give yourself a reason to be proud of how you spend your time. It can be as simple as doodling in a notepad, and be proud that you expressed something instead of sitting there marinating in something.

Go somewhere secluded, and scream really loud. Once usually does it, but it can feel good to just get it out.

Find somewhere to volunteer; it'll keep you occupied, and help give you perspective...Get you out of your own head for a bit. If that's a "no," just get out for a walk like other people said. Put your eyes on new things; get some fresh air.

Good luck; keep moving and you'll find your way.