You did not say how old you are now. Do you eat junk food a lot? If yes cut down and try to have a healthy diet. Before you masturbate, wash your hands with antibactereal soap. Inserting clean fingers inside your vagina is better that do it through your panties. Use a washed pair of underpants everyday. About the odor you are scared of, you should try getting scented lube. They come in various diferrent flavors. Use those with and your fingers. You should not get any odor. If problem still occurs, please go see a gynocologist and do a hormone check.

Just wash hands good, and just wash ur vagina very thourgh and clean. My best freind uses summers eve, and I have no problem wen I finger her/lick her vagina.

This would be my sister talking now:
hey..Just readign what you wrote, you can try this... It worked for "somepeople" use a good size cucumber and get some k y jelly....Look at some porn, or anything that gets u off adn play with urself . After incerting the cucumber inside completly, take it out and finger urself . Just go in slowly.
After a while u'll get over the fear of using ur own hands.

Also have fun..Enjoyr your body...