You have absolutely no rights or recourse in this affair (no pun intended) because you are not married and never lived together long enough to even approach the definition of common-law marriage (if your state even recognizes that).
You've been used and you just let it happen, even suspecting this man would cheat on you. Now you're upset because you saw this coming and you didn't do anything about it. That's why you want to sue him. I'm sorry you were used this way but you never loved this man, he was just a partner of convenience. Now you want to believe you loved him because you've lost all the material benefits he might have provided you.
It is totally absurd to even think a man would go to counseling to correct problems "you" think he has before he even becomes married. Come on now, get real. What made you believe you could dictate to him what he should do? That is probably the reason he decided to move on. Now you should move on too.






