OP, I think you actually know what the answer is but you're trying to persuade yourself to make a more practical choice.
You couldn't go through with a termination at 7 weeks. You say you feel attached to the baby now and that you feel "broken" at the idea of a termination. You're also 40 so this might be the last pregnancy.
You say you could cope emotionally, practically, and just about financially too.
Honestly, I don't really think this is even a question. If you wanted to have a late-stage termination, I wouldn't be trying to encourage you otherwise. Your body, your choice. But there's nothing here that suggests you want a termination and I worry that you'd really struggle to come to terms with your decision afterwards.
I went for a termination at 8 weeks and couldn't go through with it. That was 15 years ago and I now have two beautiful teenagers (it was twins). I was a single parent and a potential carrier of a genetic condition, so I know just how bloody hard it is trying to figure out what to do.
The advice a PP gave you is really good, and it's how I reached my decision. Close your eyes and imagine six months time - firstly with a newborn, and then with no baby. How does each situation make you feel? I found I had an instinctive gut reaction - and it made me realise that deep inside, I'd already made my decision.
In your situation I had the babies and have never regretted it. From what you've written it feels as if that might be the same for you? It's a hard situation and there's no judgement whatever you decide 💐