Thank you everyone for your replies.
I smoked more before I had the children, and 3/4 a day after, but gave up 3 years ago. This has caused some bone loss I believe. However, up to 9 months ago the dentist was saying she was quite happy with my mouth, they have never suggested hygienist or any treatment.
However this year we have had a lot of stress from work and elderly parents, also type 2 diabetes and menopause and I believe that these can all be contributing factors. I am hoping it will improve with regular maintenance - however, this front bottom incisor is quite mobile and I couldn't see how a partial denture would be fitted and stay secure.
I have been frightened of the dentist all my life, was just starting to gain a bit of confidence and now this has knocked me for six.
Jane
I was terrified of the dentist too, thanks to a really bad experience almost 16 years ago. Thankfully I found a really gentle, kind dentist recently. I had 7 teeth extracted and I can honestly say, I didn't feel them coming out. How he took them out without me realising they were gone I don't know. Whatever technique he used, it's a good one. I have one more tooth to come out in a few months time and I'm not at all worried about it.
Stress can knock eight bells out of your system. I know this only too well. Interestingly you mention Type II Diabetes. Thankfully, that's one disease that's not in my family. However, my late husband was Type II. He also had serious heart disease. His teeth just seemed to go all at once. First, his four screw in crowns at the front fell out, then his molars went loose. His whole mouth was a mess, yet he also didn't smoke and very seldom drank.
I think there are many factors to gum disease. One very interesting thing I learned a few years ago was that fluoride toothpaste, although preserving the enamel on teeth, destroys the connective tissue between the gums and teeth, forming little pockets and ultimately, mobile teeth. There's quite a bit about the downside of fluoride on the internet.
I still use fluoride toothpaste for my natural teeth - one of the ones made specifically for smokers.
The other thing I've noticed, at least for me, is that only certain teeth/parts of the gum have been affected. I still have several teeth that are very firm and showing no signs of becoming loose or the gum receding. Why this is, I don't know because I would have thought if one was affected, they all would be. Perhaps one of our lovely dentists here might have an answer to that.
A single tooth denture is an option and would be quite stable as they are precision made, often with little clasps that fit to your other teeth and your adjacent teeth would hold them in. My lower denture has 3 teeth in the front (the middle ones), space for my 2 two teeth on one side and 3 on the other then I have some nice plastic molars each side. I don't need to use any denture adhesive on the lower as it is a really good fit. Took me a while to learn how to take it out as once it was in, it wanted to stay there

I've got it down to a fine art taking it out now
If you look at partial dentures on the internet, there are some really good sites that show you the different types available.
One thing I have found since my teeth went mobile a few years ago was that, I tended to brush very gently - too gently incase I knocked them out which meant that my teeth were not getting the proper cleaning they should have. Now that the loose teeth are gone, my remaining natural teeth get treated to a good clean at least twice a day. Too much tartar build up also loosens teeth so that's one thing I'm trying to avoid.
Please don't let this knock your confidence too much.