I can relate to you in that I have also shifted a lot of people who have not been good for me out of my life. I have not the time or energy... and have to look after myself and my physical and mental health now I'm getting older....to deal with certain people.
The ones I have let go of ['friends'/family...long story] have in the past been judgmental, critical, mocking, used me and generally not made any efforts to see me or be supportive, plus been downright rude and/or hurtful. And I've had enough. Seriously. I've been helpful, cooperative, consistent, made efforts to visit and be there for these people, only to forgotten or disregarded. No More. I cannot absorb any more hurt.
You sound hurt and hurting. I think texts can be misunderstood however and better to address the person face to face and sort the issue out, see their facial expressions, see if they are genuine and still wanting to be there for you after they hear your feelings have been hurt.
Often it's not the incident itself that is the decider but the fact it's the last straw. If someone has continually made you feel bad about yourself and you always come away feeling like rubbish when you see them...you go home feeling worried and agitated, then they are not doing you any good.
Just stick with people whose company you enjoy and when you leave them you feel warm and fuzzy. Try and make new friends, maybe it's time for you to change your social circle, new hobbies/activities etc.
But all is not lost, they all want to contact you so tell them how you feel, give them a chance to talk about it because you won't have lost anything by doing that. Your mum...when she is behaving see her and talk to her, when she isn't being fair don't engage on the phone, text or in person and explain why. Then she has the choice to be civil or else lose out.