Have you considered his anger may be part of the reason you cut. Or, that you cut to get his attention, even negative attention? Cutting is not the answer to dealing with stress. You have been cutting a long time and still have the stress.

Seeking help for someone you care for is not pity. It is the thing people do when they care.

You have built quite a formidable fortress around your rationalizations and illogic. You may choose to continue being miserable or worse; or, you may choose to make a better life for yourself. If you do not get help, there will be a price to pay.

Good luck.