I'm really sorry to hear things are so bad for you at the moment and can appreciate how upsetting this may be. First of all, can I say that you certainly aren't a failure as you obviously keep trying different things to move your life along and that takes strength and guts and the fact you are all doing this suggests you are very determined. It is just unfortunate that you haven't had a lucky break so far, but that isn't your fault. Often things happen which are outwith our control as you probably already know. Keep on in there, I know it is hard, but something will work out eventually.
The fact that you say you still live at home, I would imagine your parents are still there. Can you confide in them as to how you are feeling? I'm sure they would want to help. Also maybe it would be good to chat to your GP again to see if there is anything he/she can do for you. Have you thought of social prescribing where your GP can refer you to a class/group/activities in your area which can help your physical/mental well-being? It might be an idea to join a club/group where you could meet people for some company or take up a new hobby. Just a thought as you never know, this maybe a good way to meet people too and boost you chances of something romantic. Also there are lots of online dating groups to think about too, although I realise that isn't for everyone. Please don't be disheartened on the dating front as I am sure there is someone suitable out there for you.
I know it is very hard to get work in this current climate, but keep on trying with that too. Have you thought of voluntary work in the meantime? Often employers place a lot of emphasis on voluntary work and it can sway in your benefit if you have done this.
I know it is very difficult staying positive, especially when things aren't going your way, but things will improve, although I know that is easy for me to say. I'm sorry I can't be of more help, but I'm sure others will have suggestions too and will post. Just wanted you to know that I was thinking of you and wish you well in everything. Good luck and take care. Aileen x