So, i have a question that has been lingering in my mind. Is it wrong to be very happy with my significant other than my own kids? When im with him its like the most awesome feeling ive ever had. Ive never had a relationship like this before, someone who really cares and loves me someone who says he cares about my success and happiness. Who is supportive in everything i do. Or decisions i make. Its like when im spending time with it. I feel comfortable, just happy. But when i spend time with my daughter its like i have to be this other person like i always have to prove something, and everything i do feels wrong, and she says negativity things at times when i conversation with her. She makes me feel irritated at times. Honestly being or spending time with her i rather not do. Then again i feel bad… btw i wasnt around or raised her at all. I barely started to have a mother daughter relationship with her about a year ago. Not to mention shes 20 yrs old and she lives with us. Its very hard with the 3 of us here. Like i always have to split my time. Although my significant other works 10 hours a day 5 days a week. So its just me and her home all the time. Then i like my alone time also… i dont know how to handle this situation. 
Well it sounds like you don’t wanna spend time w her and you don’t have a relationship. Kinda get why she’s pissy w you.
You have two options to change it: change your relationship w her by working on yourself and the relationship. Or end the living situation ergo she moves out.
What about some mother daughter therapy…sounds like theres alot to unpack there…
Having read a few of your posts, it sounds like the living situation isn’t the most ideal or healthiest for your daughter or for you. As Starlight says, there must be a lot to unpack there and therapy would be a really good avenue for that. Idk if you two are open to that.
I can understand how there would be really hard feelings on her side. Sometimes the past and the consequences take a long time to heal from and we need to acknowledge that. Especially when we have hurt others. It is hard, really hard, and really necessary IMHO to acknowledge and sit with the pain we have caused others and do what we can to repair that.
Your feelings sound to me to be normal, you feel bad around her because she reminds you of ways you let her and yourself down. It is freaking uncomfortable as hell I would imagine. I feel for you both.
It isn’t wrong to not want to be faced with our messes. And it isn’t wrong for her to feel let down and negative toward you. As Faughx says, you have a choice. Do you want to work on your relationship with your daughter, maybe offer her some healing and love that she didn’t get in the past? If not, then is there a family member or friend she could live with?
It sounds really sad for both of you and I hope you can both find some healing and resolution. Sometimes we can reunite and sometimes we cannot. Wishing you both peace.
Everything you said is correct. It is hard and uncomfortable. I know i admit when in my addiction ive hurt her in so many ways. Again its hard for me to heal and forgive myself for it. Thank you for understanding. Im going to do therapy first. Than bring her along. There is alot to be said from the inner core.
Thank you for receiving my response in the spirit it was written…healing for you both. 
I forgot to add two things… 1) thank you for sharing so honestly and vulnerably; and 2) that you can both be happy…it doesn’t have to be an either or situation.
We all have a ton of healing to do, certainly I do. Learning to forgive ourselves and to love ourselves helps so much. Glad you are here.
It sounds like family therapy could be a course of action getting down to what the main problem or problems maybe . I kinda had the same problem but with family being parents but it just kind if worked it self out with my dad but my it was therapy for sure there was no getting around that with my mom