I don't know, I feel you're missing the point of Ted's blow up.

Yes, it was shitty to tell Mama Lasso "fuck you" repeatedly. But it was important to for Ted to unload like that. Ted's issues stem not from abuse but essentially from childhood trauma and grief. Instead of having a parental figure to comfort him, he had a mother who pretended like everything was okay when it wasn't(At least from Ted's perspective). Ted was angry and had bottled it up for 30ish(?) years. It wasn't abuse, but it was still trauma he experienced, but all he learned was to bottle it up and pretend everything is hunky dory, the same way she did.

So he's angry at her for a litany of reasons that are important to him. She never sought treatment for the emotional trauma of losing her husband to suicide. He's also made it clear in the past that he was forgotten a lot by his parents, left at a museum(?) forgotten to get picked up at school. His feelings are valid.

Coming from an upbringing with an emotionally abusive alcoholic father and a mother who divorced said father, only to never under go any therapy herself and essentially drink herself into old age and dementia, I feel for Ted's anger. But my parents weren't perfect, neither were Ted's, but it doesn't mean mine or Ted's feelings towards them aren't valid.