Anxiety, panic. What do i do?

Hi! I think i am experiencing mental anxiety for quite some time now., i am having problems like - lump in throat, tiredness, stress, and headache. the problem is that a person started acting weirdly with me, treading a thin line between flirtation and being a concerned human being. he would ignore my messages deliberately for days, then suddenly start texting me. i had doubts that he liked me but since he was my senior I dare not ask him for 2 months. Then I confessed my feelings to him at the deliberation of my friends and he kept me on hold for 2 more months till i decided to give up because he won't clarify. he is basically given to cheating in relationships and flirtation. my friends find it acceptable according to the new modern ethos and they feel i am conservative. whenever they bring up his name, and talk about casual hookups being the norm, i feel cheated since they don't know the trauma i've been through, that he manipulated me psychologically. what do i do?