Recession

Hi all. I have recession of my gums which dentists said that in the future will cause me problems. I am only 26. I always thought it was from brushing too hard because I used to be really hard on my teeth and gums. Well I am starting to think (since I've changed the way I brush) that there must be something else to the puzzle since I still have areas of gum that wear away and expose part of the nerve. My gums seem to be very sensitive and I try my hardest to brush lightly. I don't feel like my teeth get clean though and afterwards if I run my nail along the gumline I get plaque off. I want to switch to a natural toothpaste without flouride but just haven't known what to get. I think my gum problem is from the chemical laden toothpaste I've been using all my life. What do you all use? Have any of you had the same problems? Also I would like to whiten my teeth but doubt any of the products on the market are safe. Anyone have any suggestions? Thanks!