How do i know hes for real?

ok, i am the typical gurl who is so shy and so self conscious given the fact i gained a lot of weight within a year and broke up with this guy i thought was the one, i find it overly difficult to approach guys or tell a guy i have feelings for him, my self esteem does not exist completely cause i know guys will never go for me anyhow.

met this guy last year at a uni party, came across so confident and seemed to have an interest in me. Recently its been like wow where did this come from. he thinks hes gods gift, hes got sum overdosed ego, and he seemed to want a yes from me all the time. He called me once tellin me abt how hes now developed sum interest in me and then said to me 'im gna be straight u nt the only gurl im feelin right now, i dnt wanna lie but thats the truth'

at the moment hes so eager to see me well sleep with me more like, told him straight hell no, but hes like kk jst come see me.

He wont take no for an answer and seems to persistant, at the same time im wondering why is he this interested in me, whats that about.

Weird thing, my friends say hes quite ugly, i shuld stop talkin to me, but all of a sudden im so attracted to him, even tho hes got sum crazy attitude to him.

I really dont know wat to do?

How do i know hes being for real?