oh @TheresGotToBeMoreToLife, have a massive hug!!!
your boss is pretty much on the money in my opinion.
My own relationship history has shown me that when we come out of a significant relationship, the hurt and trauma of this means that we are not in the right space to find Mr Right, but we can find a Mr Alright. If Mr Right rocked up, we'd not be ready for HIM! So He'd not find his Ms Right, because we need to do some healing/work/growth to become the person we are supposed to be.
I firmly believe that everyone that comes to our life teaches us something, but it's a lesson to be learned, and when that lesson has been learned we need to let go, so that we can be ready for the next lesson.
I believe that you displaced all your grief over the death of your marriage by starting this relationship, you never allowed yourself the time/space to grieve the end of your marriage.
now that this Mr Alright has gone, you're feeling the full force of the loss of him AND the marriage.
Someone mentioned upthread that you could be depressed and to go the the dr to get a prescription. I don't necessarily agree with this. (and that's speaking as someone who almost died with depression 20 odd years ago)
What has happened to you is sad, very sad, you have had a couple of major blows to your self esteem and stability. You're supposed to feel sad in these circumstances, so feel sad! cry, rail at the injustice of it all, then deep breath and try to work out what you can do to make your life better as it is. Gym is a good shout, the endorphins will help lift your mood, go swimming if you can - the water blocks all the sound out and you can let the water hold you and it's very freeing.
There have been times where I was destroyed by loss of relationships, abuse and neglect, then a brush with a few odd balls and one person who was very odd in the end but utterly stole my heart at the time. When I lost him I thought that was the end.
Reader.... if you could see through the screen now, you'd be shocked at what my life was and what it is today. I may be in my 50s, but I am loved and cared for and in a beautiful place in every imaginable way.
Never ever give up on yourself! have faith love and be the best version of you that you can be, it's a work in progress, but it's worth the effort. Then you will learn that you are a person who is a good enough human being and anyone who has you in their lives is lucky.... then my love, you are ready to be loved.
I never believed the Love Yourself First thing, but let me tell you, it's the best thing you got. Don't fight life, embrace it and it'll be ok.