A few minutes into sex, the outside of my vagina starts to hurt so bad we bad we have to stop. I produce whiye milky liquid, no STD or uti. Whats up?

Likely due to yeast. Yeast infections commonly are associated with vaginal soreness, whihish discharge and pain on intercourse. Severe itching is usually present. There are many antiyeast preparations in any drug store. Good luck.
Pain during intercor. You should chech with your gynocologist to be examined and find the cause. You may have a infected Bartholin's gland cyst. Bartholingland cysts are located in the skin under the labi, they are usually palpable and often get infected and are painful. It could be some other condition but milky white fluid suggest it related to Bartholin's gland.