I don't think gingivitis contributes to loose teeth? Gingivitis is something I got semi-occasionally back in the day and it usually just went away after a while. I'd be more worried about a dead tooth. If you're not brushing enough and you get a cavity and it reaches the nerve it could've killed it a long time ago. Best case scenario is it falls out, worst case scenario is you end up in the ER from abscess complications.
Probably not that extreme, but quit loving with it anyway, and just start brushing your teeth more often. Try and cut out as much sugar as possible for as long as you can and drink as much water as possible.