How do you know you have a yeast infection?

i have an embaring problem. i need to go to the doc. i dont what i have. i hope its nothing serious. i had this for 2 years. i thought it would go away on its own but it hasnt. it got worse. at first i noticed i smelled kinda funny. it didnt stink real bad. just had a funny smell. and now the smell has gotten bad. it smells different. it really reeks. it smells similar to a trash can,rotten fish, wet carpet and wet clothes left in the wash machine for hours. that really gross stinky smell. im sick of smelling like a trash can. im so embared. people can smell me unless i wear a thick pad. and i leak down there. its like a thin liquid. like pee and it soaks the middle of my panties- the part where u stick a panty liner on. i have to change panties a lot and wear pads so my panties dont get wet. when i get out of the shower i can feel the liquid trickle down my legs. its like pee but its not. its clear like water.and thin. sometimes when i wipe i get white goo but not often. ive always had that. even when i was a virgin. but i think my bf may have gave me something. i never had any problems till after i met him. we did it. its my fault i didnt use protection and just trusted he be clean. what could i have? does anyone know? and what could help? also many times when we had it feels like something is stuck in the way. and i can never get pregnant either. so i wonder what is wrong with me