There are so many similar stories to mine on here, it's quite scary.
With regard to red flags, I think there were a few but it's only on reflection that I can see them, he was my husband and I loved him warts and all when we were married. I always took his side when he said other people were against him.
I always thought my H was a nice guy, but actually he wasn't, he just told me he was enough times that I believed him. He had a dream of moving and living in France, so me and the DCs moved here, but then he never followed. He stayed in the UK all week and then lots of weekends, told me he was lonely and unhappy so needed money to go to gigs and pubs. I was left isolated in France away from my friends, in a half-built house, two young DCs, one with special needs, working full-time and then some from home for a pittance. All the money I earned went into a joint account and he then gave me £300 a month to live on because he needed the rest because the UK was so expensive. He was on £36K himself. I had no heating, barely any food, couldn't pay the bills. I look at photos taken of me back in those days, I look sad and lost.
Then when he came to France for the weekends he did nothing, didn't interact with the kids apart from to watch a video with them or playing video games, that's if he wasn't sleeping on the sofa. Would criticise my parenting, housekeeping everything.
The week he left he cancelled my card on the joint account, I couldn't open a new UK bank account because I didn't have a UK address at the time, and my UK employer couldn't pay me.It got so desperate me and the DCs ended up at a food bank. When I told him he shrugged his shoulders and couldn't give a toss. He had been taking his partner and her DCs to fancy restaurants, Pizza Express, while mine were being given homemade bread and jam and being told it was a treat.
He needed his parent's approval for everything, if he ever said anything they wouldn't like to hear, he always started the sentence with Brittany says... I just thought it didn't matter because they'd never liked me from the start.
He told my best friend that I didn't like her DH - she only told me this at Christmas this year, which was a year after her DH's death. I was devastated that XH had said such a thing, fortunately my friend is smarter than me, she'd realised a lot sooner than I did that XH would say things using my name, when he really meant his own feelings. She says, she never told her DH that my XH had said those things. I hope not, they've been my best friends for 20 years, I'd be heartbroken if he died thinking I didn't like him, I loved him as if he were my brother.
XH and I were together for 20 years, married for 17, but he has not one friend now from those 20 years previously. He doesn't even have a friend who met me.
I can't look at him these days, but I would struggle to have a conversation with any man that treated their DCs as badly as he treats his.
And with regard to having another relationship, I never will, I've had a couple of near misses in the last couple of years, but I just can't bear the thought of being tied to another man again. I like my freedom these days but most of all I like being happy and having control over my life.