I just want to say that I feel NO ONE should ever totally invest their own SELF into another. Love is blind. It also does not mean ownership of someone else. I found that out the hard way. It's amazing how easily love can turn into something very much different. You never REALLY know the person next to you even if you've been married 50 years.
People also change over time. Sometimes two people can't live on the same page.
It's difficult to try and understand why someone who you believed loved you would betray you. The fact is people are people first. Individualistically. Always put your well being first and before even your greatest loved one because if you are let down you will be destroyed and not know what to do or how to go on. You've turned your autonomy
and self reliance over to another. Sure it hurts to be betrayed. Of course it sickens you.
But why be surprised ?
In closing , it's unfortunate that true trust and true love is more valuable than gold.
Please take care of yourself. Get help. Put everything else second , including your grandchildren if need be.

I hope you get thru this and come out stronger.