I’m so sorry you find yourself in this situation. Is it really unsalvageable ? Before I lost my husband we had been married for 40 mostly happy years, but I have to say I recognise the pattern of your husband’s present behaviour, because my late husband went through a period of depression which manifested in something similar. Men are generally awful at admitting they have any kind of health problem, so maybe start off by having an honest conversation about the obvious deterioration of your relationship and establish if he’s having mental health problems which may explain the behaviour. You say you were ‘love bombed’ in the beginning, but there must have been mutual feeling there once, so it’s worth exploring whether there’s anything left to build on before you decide to part ways.
I can only comment from the point of view of having been widowed a couple of years ago in my late fifties. - from your post, a similar age to your own now. We had been happily married for 40 years and it was very sudden. I was still reeling from the loss the following year when I met the man who is now my husband. It was a chance meeting and at first I couldn’t consider a relationship as I was still grieving. We became good friends and he helped put my shattered life back together. We moved in together a couple of years later and are very happy.
I know it sounds a bit like a fairy tale ending, but we’ve had our ups and downs, and I think the best advice I can give you is that there are some good men out there, but the way forward is not to jump too soon. Although it’s different if you’re widowed, a break up or a divorce is still a loss and can bring about depression - it’s another form of grieving for the loss of your relationship and the future you thought you’d have.
Loneliness is a big factor in these situations and it can drive you to make unwise decisions, but I think you’re far more likely to be successful if, when you do meet someone, you’re good friends first and allow the relationship to develop over time before making a commitment, thereby making sure that when the ‘novelty’ of a new relationship wears off, you are compatible and have a solid foundation on which to build a future. Slow and steady wins the race, as they say. It can be done, and I wish you the best of luck, whatever you decide.