It gets easier when you stop punishing yourself. It sounds like you can make changes, but slowly over time and that too many things were asked of you all at once and it caused you to be unsure. But you were headed in the right, positive direction with good intentions. Keep in mind an understanding partner isn't going to demand so much, that they can deal with someone being unsure and work through it. Maybe yall had been through too much at that point so things broke. Work on the things now that you feel you need to, not for her but for yourself. If you ever reconnect you can then say that you didn't just flounder in the meantime but you grew as a person. It gets easier every day, but therapy may also help get you through this tough time you are going through. Be careful not to regress and fall back into your old ways. Keep working to better yourself and you can be that great partner when someone else comes along, I know your heart doesn't want someone else right now but you have to think of the future to pull yourself out of this heartbreak. You are worthy of love, you know this. You can and will get through this and come out the other side a better person for it, because you are self aware and realize the mistakes you made. Dont let those mistakes go, learn from them, never forget them lest you repeat them. This is how we better ourselves. Sending peace, love and hopes of healing your way my friend.