Hi ~ I'm so sorry you're having so much trouble. I do understand. It's difficult when you have unfinished "business" ~ such as things you wish you had done with/for your mother. I also feel like that about my Mom. And I too had trouble with my oldest sister ~ she has always been a trouble-maker, and when Mom died, she started trouble again even tho she hadn't come "home" in years!!
Please don't feel guilty about what you think you should have done ~ your Mom DID understand, believe me. And she IS with you ~ have you ever sensed her presence with you?? Haven't you smelled her perfume or just felt her being there?? Well, she's there. She's watching over you because she loves you. If you haven't felt her yet, it might be because you're too upset ~ just be calm and you'll feel her.
And remember that we DO see our loved ones again ~ when it's our time and God calls us "home" we'll be reunited with our loved ones. We just have to WAIT until God calls us.
In the meantime, try to enjoy life as your Mom would want you to do. Take care of yourself ~ and God bless you. Hugs, Lee