Some parents don't even realise that they are mentally abusing their children, and they don't mean to do it. But we as humans, tend to take out our frustrations and anger on those that are closest to us, and we love the most. Especially now that you are a grown man, she probably sees you as 'strong', and forgets that you are still her child and her words can effect you more deeply than they would a stranger.
Though all are said with the best intentions, majority of the advice given here isn't going to help because we don't know the full situation. The best advice given here is to see your GP about an Action Plan.
Good on you for seeking help, that's a big step. Good luck with everything mate, I hope it all works out well for you.