How can I become more likeable?

I'm actually a very likeable person, but I find myself pushing people and potential friendships away because of my insecurities. If people try to befriend me, I get offended because I think they're only doing it out of pity. Deep down, I actually like who I am - but i'm in my early twenties and insecure about my job, where i'm going with college, money, etc. Is this normal? Why can't I relax and just accept myself for who I am? a psychologist told me I set my personal standards too high. Any suggestions for correcting this? I've tried yoga, medication and other forms of relaxation. No such luck..