* correction: not an STI, probably yeast infection.
You can check out the mayo clinic site, for further descriptions and treatments.
Hi,
A white discharge from the vagina is normal for most women. If you notice a change in color like yellowish or greenish, and/or an strange odor accompanied by itchiness it could possibly be a yeast infection or STI. If you think it's an infection, contact your Dr./gynecologist ~ both are usually easy to treat.
Good Luck
You will get answer from some one who knows about the substance you mentioned. Masturbation is okay. It is a natural habit and a safe way to get sexual satisfaction. As you have not sexual contact with any one , there cannot be any Sexually transmitted Diseases.