你在說什麼？

I don't think so

No clue. Sorry

I'm not sure you can do that. You can't change your entire thought process but you can think new thoughts and focus on them. If you focus on different thoughts, you almost become a different person, gradually. I think that's what's implied here.

If it's not realistic for you to go back to university, you have to look at the best option for you now. Everyone makes mistakes. I wish I did a lot of things differently when I was younger. I know it's easier said than done but you have to look ahead.

Start small. If you want to develop the habit of reading for instance, start by reading one page a day, but do not skip it. Gradually you can bring it up, though reading a page a day is also good. If you cannot read a page a day, maybe reading is not for you and try a new habit.

True. I take the never look back as meaning 'dont go backwards'. Even that's not realistic, there will be times you fall back, just remember to rise up again.

My pleasure

Understand that you were probably not a good person but you don't have to remain that person. Guilt and regret is at least an acceptance that you were wrong, a lot of people don't even get to that point. The next step is to try and become a better person, and forgive yourself for the person you were and the things you did.