3 years and the same fights..;.need help on this one please...very confuse...

It's been 3 years with my spouse and the fights are about the same things over and over again.Things would be fine for a few weeks sometime a month not even and then he would do something most of the time to start fights,example:he has these constant mood swings,i guess the fights is about me not living with him and his acceptance towards this could never change to the fact that i work from home, raise my kids from home and so on.It's been like this for the most part of our relationship and he can't accept this at all.When we have an argument he would text me the same things over and over again example:he needs a mature woman,he needs someone at nights etc etc ect..

It's very frustrating and now he started seeing someone else behind my back.I saw a text message on his phone that he forgot to delete. Last Tuesday we had a big fight concerning a burning in my urine that i wanted to get checked out and instead of being supportive or loving he said i am accusing him of giving me an STD which i did not.One reply i got from another post i have up is that i should have gotten tested without telling him and then get the results after then confront him,but i think his reaction would have been the same.So last Tuesday dated on his phone the same said date we had that fight concerning my doctors check up was a text message on his phone he sent to someone saying"meeting you tonight''.

I think he is suffering in his own way in this relationship and i feel very sorry that i can't live with him but does this give him the right to cheat on me? i don't even know how to address this now after all the police reports i made from the last threats,his reactions from the STD he may have given to me,which came back negative but his reactions to this sold him out,one person says he is pissed i accused him first without finding out for sure but i never told him anything about the STD and this have me very confuse.I think that he has been cheating on me about a month now after he started losing interest in me and started going out a lot at nights saying he is at the casino.

I don't know how to go about handling this,I really want him to ne happy and so do i want to be happy and if he starts cheating then he is not happy which tells me that this relationship is at it's breaking point.I want to end it but i am afraid that if i don't have solid enough evidence he is going to make me feel like i am going mad...he always does..i did not tell him that i am aware of this and i dont know how,any advice here would be greatly appreciated...

lovehurts...