You’re absolutely not being unreasonable. It’s natural to feel angry. Homelessness at any age is traumatic. And parents should always be there for their kids.
Your story resonates with me. My dad left for another woman, v insensitive about it, wasn’t there for me and died suddenly, when relatively young. Mum always difficult due to her own dysfunctional family, got worse after divorce and v self-absorbed since. Even in my darkest, saddest moments she’s said heartless things and made it about her. I’ve tended to take the parent role to her, taken her on holidays etc. When I was severely depressed and facing homelessness with kids, she made it clear I should expect no help or even moral support from her: “what can I do?”.
Like you, I’ve always been sensible, studied and worked hard and been financially self-sufficient. But, for me, the emotional and mental side of things have been the challenge.
As PPs have said, I strongly recommend therapy. In my experience, the NHS can’t offer a great deal (usually basic CBT). So if you can afford it, you may need to pay. But, with the right therapist, this would be money well spent. I’d put in as much work as possible before entering any serious relationship, because (in my experience) unresolved rejection from parents can affect relationship choices or lead to unhealthy dynamics. As PPs have also said, I wouldn’t worry about your parenting, as you’re clearly v earnest and, most importantly, aware of it. My experience has made me much closer to my kids, we can talk openly about problems and they know I’ll always be there for them.
Once you’ve come a long way with individual therapy, it might be worth discussing with your therapist whether joint therapy with your mum would be appropriate/beneficial. She may have learned behaviour from her own parents (in some working class families back in the day it was a common view that once a child had left home they shouldn’t expect to come back). And, due to her own struggles, she may not have had the space to reflect how she’s affected you. If it went well, it could be v healing for you. And if she refused or it went badly, it may not make things much worse. You’d have to decide that. But, if you want to talk to her, doing it in a controlled environment, with a therapist to guide you, might have a better outcome.
In the meantime, as PPs have said, I’d set firm boundaries to the relationship. Certainly keep contact fairly minimal and superficial (e.g. feast days and birthdays). I’ve coped by not expecting anything or sharing much. It’s a work in progress, but staying in boundaried contact has been best for me, as a period of no contact caused me much more pain and was stressful for others, including my kids. Also, look to others in your life to be that motherly or fatherly figure. People who really care about you and you can fully trust. Is there anyone (extended family, family friends etc) who you might be able to develop that sort of relationship with?
Finally, while the above are ideas to move forward, don’t feel responsible for resolving things with your parents. It’s their responsibility. You’ve made an excellent job of the hand you’ve been dealt and should be so proud of yourself.
Sending strength and love ❤️