Yeast infection

Kim
How do you know for sure that you have a yeast infection?
I'm not sure if I have one but I seem to be getting some symptoms.
- Burns when I pee
- When I wipe it burns
- I have been discharging a lot more than usual and its light brownish to a creamy color 
- In my inner lip I have white residue (the best I could explain it)
- between my vagina hole and the butthole seems to be where the burn is coming from
- also if I touch the vagina hole it hurts like I'm not sticking anything in it. Literally the outside of it when I touch it cause it seems to be the location of the burn too