Betrayed!

I have been with my partner for 28 years, I have been loyal and faithful the entire time. We have both been pot smokers however he is much more dependant than myself. Of late he has run out and become very hard to live with. I have been very supportive of him to the point that for many years I have done the paperwork for his business for free I have never been paid. I contribute to the household being responsible for all the washing, shopping, cooking, cleaning etc. for which I pay for and he doesn't do anything around the house. He pays the bills which I appreciate, I have also paid large sum of money towards our mortgage to approx the value of $60,000. We have 3 children and only 1 now living at home. Since he has run out of pot he has been very abusive and hard to live with being nasty and very intolerant of everything in his path. He handed me his phone the other day to help him with a map application. It was coincidently opened on a message between him and he mate...........his mate said......I feel sorry for you mate..........and his reply was...........it's not your fault, I married the c*n!..........I am devastated!!! It is like the worst insult ever! I don't know what to do, I approached him and he turned it around to me over reacting. I have been a good woman......I don't know what to do!!,