Manager constantly asking me to work extra hours

[user18192929]

So 9 months ago I reduced my hours at work from full time to part time due to my health. The past 3 months we have been short staffed and my manager is constantly asking if I can stay later, start earlier, come in on my day off.
I have explained to him that the hours that i do are enough and I don't want to push myself to do more. Today he accused me of not been a team player.
If I had known he would constantly be asking me to work extra I would have reduced my contract a bit more so that I could work the extra hours for him and keep him quiet.
AIBU to just want to work the hours I am contracted to do?

I think you need a new job?

YANBU and you are entitled to work your contracted hours.

Have you spoken to your boss's boss?

Have you repeatedly explained if you work extra you will end of sick?

I would be tempted to do some extra hours then go off sick... hammer the message home?