I think when we feel like something doesn't feel right that that's a good thing and usually correct for us, even if the situation isn't exactly as we see it.

I love being with my husband and though I'm okay on my own during the day, I really don't like not being with him at night.

Depending on how you would like things to be for yourself, you may want to work on enjoying your own company and becoming more self-confident, etc. I don't think healthy/unhealthy is a very helpful dichotomy; you're unique and have your own needs and ideas of what you'd like and what makes you feel good. That you're less anxious when your boyfriend is around is great except your boyfriend can't always be around :-) Were I you, I'd explore that a bit.

I'm looking, for myself, at things I need to work on in case my husband dies before I do, the things that make me anxious about being older and "alone" and seeing if I can't become more confident in myself and create a bit better support network, etc.