I think you need to think about the people giving advice here. I suspect quite a lot of people saying £9k and no apparent savings at 44 is fine have quite a lot of debt themselves and they find it soothing to say it isn't a real problem. I don't have any debt and am comfortably off and I can say I think it is a big deal.
Frankly, given that he has no plan, commonly known as a budget, I think he will just meander on as he is. Don't under any circumstances let him sell his house and move in with you paying rent. When this palls you will then be in the position of kicking him out and making him homeless which will lead to endless hand wringing on your part. Whatever you do, don't marry him and put him in the position of being able to claim part of your house.
I know he's a fair way from retiring but has he got any pension provision made or he is just planning to latch on to some woman and share hers?
Person after person have warned you and yet, even with your mother's example, you still dither. Yes, a few people have said that it's not a big deal and you seize on to that. Do you really really want to repeat your mother's mistakes?
The only way that this would work - even remotely - is that you take total control of his finances, give him an allowance, and organise as speedy a repayment of his debts as possible and seeing if any lower rates etc can be negotiated and so on. This is as exhausting undertaking as you basically become his caretaker and it's hardly romantic and there is always the risk of backsliding if he's not truly on board with this plan. To put this really bluntly, why has this supposedly eligible chap not been snapped up - I'm prepared to say his hopelessness with money is probably one reason. I think he possibly got his house and mortgage under the influence of a previous girlfriend and then she got fed up with being his mother.
My mother did all the finances, planning and worrying. She looked careworn compared to my much older father who never worried about those things. When I married I particularly selected for a man with a backbone and who would take his share of the mental load. People rabbit on about shared interests and the importance of communication, sharing your feelings, a sense of humour and so on but I would put having a man who was a self-starter with nice manners and no disgusting personal habits well above those ephemeral things.
I think all these warnings are likely to be for nothing as I think you will seize on anything you can rationalise into a reason for continuing the relationship. I understand that starting over again is hard, very hard. I once spent a fair bit of time trying to be totally adorable to change a commitment phobic's mind about marriage, children etc. I was besotted and thought he was wonderful. My dad eventually told me that I had given it my best shot and asked whether this man given any sign that he was preparing to pop the question and I had to admit he hadn't. Sometimes you have to admit that hard as it is, you have to be back on the market. I met the man I married shortly afterwards and he absolutely was the right man. Looking back I can't believe how I'd wasted so much time on a man who was, in reality, a manipulative creep.