if you eat a lot of fruit, especially citrus-y kinds, rinse your mouth out with water after eating them.
you can also start making green smoothies - they are about 60% green and 40% fruit. the taste of the fruit overpowers the greens, so you don't taste them at all. they are a good source of calcium from the greens and there have been studies that the smoothies (the greens, really) will help rebuild your teeth and help any gum problems.
if you're using toothpaste with fluoride in it, please stop. also, brushing hard on your teeth can damage the enamel and they'll become very sensitive.
There is something called 'gum joy oil' that can be used as a mouth wash, rubbed on the gums and even as a toothpaste, that helps heal mouth problems.
another thing is snacking. if you snack a lot it can leave your mouth in a constant acidic state, which is not what it needs to be. i've read of some people brushing with celtic sea salt as it helps the mouth stay in an alkaline state.
i'll have to do some more reading up as I know of a bunch of websites and lots of other information I could post, if you want to read it.