Something that I've realised quite some time back regarding love is that if you're trying to get into a relation for the first time or trying to start it all over once again, the key is - "Showing up Somewhere Regularly".
The thing is the dating apps and stuff in my perception doesn't quite well suite someone looking for genuine long term love. So a solution that I've seen work is to show up somewhere regularly.
How this works is if a person 1 notices person 2 regularly - be it in the gym, a pub, a church or wherever, the mind of person 1 perceives person 2 as "someone familiar" with time. Gradually you could see you'll be able to exchange smiles or even small talks with each other. Person 1 may even recognise the other outside where they actually meet. For someone like you who feel lonely, I feel even those gestures would be a great boost for your self esteem.
If you feel your current circle doesn't include much girls, start creating new circles - maybe join a zumba class, dance class, yoga sessions that happen regularly or some place where you could meet someone matching your vibe...
Also something I recommend you do is to ask a close friend (preferably a girl) regarding what all improvements you could make within yourself so others find you attractive - be it in your character or even physique... Hope this helps...