What's happening to me

[DukeOfWhistleton]

I'm becoming a real bitch. I've always been a decent person. Always empathetic. Always want to help others. Always kind. But I have had some people take advantage of my kind nature in the past. To them it would have been a small thing like can I bring my kids around for a play date and they know I don't know how to say no if it's not convenient so they do anyway. We once had it where we were going on holiday to centre Parcs and they waned to join and asked to and stupid non assertive me said 'yes' when I really meant 'no we are desperate for some family time'. Anyway I've become so fed up and withdrawn socially and now I keep finding myself snapping and being abrupt and unkind and well generally nasty. I then feel awful and remorseful and subsequently paranoid that people think I'm mad or unstable. I recently went ape at someone I've known for years who has previously taken advantage of my better nature albeit not majorly. It's like I'm becoming unraveled. I hate myself right now and I don't even feel I really know myself. What's happening to me????

You are unstable you say people are taking advantage of your kind nature but they aren't to know if you are saying yes.
You then go to the extreme of flipping out. You need to start explaining yourself more and be clear and concise with people or they won't be with you.

If you think it is mental health go see your gp

With the kindest intention, it does sound like you are unstable honey being abrupt,nasty, bitchy, unkind and going ape on people isn't how a balanced person behaves.

"they know I don't know how to say no if it's not convenient so they do anyway" - I think this could be where some of your issues are coming from.

People don't know what you want if you don't let them know, I'm assuming this is where a lot of your anger issues are coming from, people are not behaving how you want them to?

It sounds like you're a nice person that's struggling a bit. Maybe you have given too much of yourself to others , maybe to be liked more, and then they haven't given anything back, leading to resentment. Maybe you are feeling low and not at your best so it's hard to offer friends much then. I lost my confidence a while back, and found I had nothing to offer my friends at that time as I was quite low, even worse, I felt resentment that I'd always been such a good friend but maybe others weren't so thoughtful.
Have a think about what might be going on, is it a cry for help, but you can't communicate it properly to your friends, that you are struggling and irritable and hope they understand? Or is it that you are really low and depleted and need to step back, work on your self care and take social friendships more slowly for a while?
Have you tried mindfulness, it helps to focus in the moment , in a conversation etc. also compassionate self care.
Take it easy, and look after yourself first.