Look, OP, please listen to this very carefully. We know that you are hurt and grieving and angry, and are very sympathetic.
HOWEVER, legally speaking it DOESN'T MATTER to the law whether what your mother did was what most people might think 'right' or 'wrong'. Or what your feelings are about her behaviour.
What matters to the law is whether what your mother did when she made her Will was LEGAL. And, from what the trained people say on this thread, it very probably was.
Also, very probably, the solicitor who made that Will acted properly also, and so you can't challenge it for that reason.
But only your own solicitor can give you personal advice. No-one else.
Please go and talk to your solicitor, and maybe also, as a previous poster has suggested, consider also talking to a solicitor who handles will disputes on a 'no win, no fee' basis. If they won't take the case on, it suggests you have little chance of winning.