got head now freaking out

gosh okay so im a vigin and slightly paranoid about health anf stuff... ive been seing this guy and up until now its just been hands and kissing basically - we went out yesterday and things were getting steamy and he ended up going down on me... cue massive freakout after because i think ive contracted every std in the book so i ask him about it and he says 'no youre good' followed by 'its hard to have anything if youre a virgin' followed by 'im glad you asked' now even tho this made me feel better for like 5 seconds im like nxious as fuck and feel like im going to die anyday now. coupled with the face that i was having a bit of a sore throat beforehand and now any worsening of that state is sending me catatonic.