I recently had sex and I hadn't in a while, well afterwards it hurt but then he went down it was fine but the next day I have had this yellowish greenish discharge and its really itchy down there. Now it burns so much when I clean down there and its coming out in a bigger amount and thick too like cottage cheese. The odor is not stinky but not the normal either,

White cottage cheese is usually yeast, treatable with OTC products.
Greenish is usually trich (trichomonas), treatable only with a prescription.
You could have both - or it could be something else.
You might as well be checked for all STDs.