“she is highly educated but refuses to work, so stays at home all day every day”
OP, ask your daughter how she sees herself ten years from now. What will,she be doing? Where will she be living? If she says, “At home, like now”, then you need to have a serious conversation. First of all, if anything were to happen to you, would half your estate buy her a house? If you were ill or incapacitated, does she really want to become your carer? One of my DDs stayed at home far longer than I would have chosen, not because I didn’t love her, but because, as I told her, the life of a child who stayed at home to look after elderly parents was never all that, and in the 21st century, it’s really not what anyone would want, least of all her for herself. Your DD needs either to do some training, or get a job. She can’t just stay at home drifting round the house and doing nothing, and it’s a parenting failure to let her think this is a possibility. As for your relationship, clearly your DD is fearful of what might happen if you start spending more time with your man, and where her place would be if he moves in permanently. She probably also fears that he just might not be quite so tolerant of her indolent lifestyle. OP, you are not being a terrible mother by wanting more of your relationship, and indeed wanting a bit of life for yourself. Sometimes you have to remind your DC that it is not actually their house - that while it will always be their home, it is your house, and the expectation is that one day, they will get a house of their own. Your daughter may well sulk or cry or shout at you- but it’s because she is fearful - of getting a job, of moving in in life, of,the status quo changing, But things will change. It’s not fair of your adult daughter to try and prevent you from having a relationship - she needs to find something in life for herself, and sitting in her bedroom just doesn’t cut it.