Shyness and Self Confidence

I lack self confidence.  I'm confident in my intellectual, academic, and physical abilities, but when it comes to relationships with people, I'm basically a stuttering moron that can't do anything.  Paralysis by analysis is what people call it.  I'm constantly doubting myself and analyze every little detail of everything that I do.  I'm still pouring over the data gained by my interaction with Julia and several other girls in the past, and every single time I screwed myself over.  I kept wondering what is she thinking, what is she doing, what am I doing and how will she react.  By the time I take action, I already lost my chance.  Katherine, Julia, Julie, Shannon, different girls every time, but always the same story on my end.  They were interested and attracted to me, but I always screw it up. Why do I lack self confidence?  Why am I shy?  Is it due to the bullying by girls I experienced in the past?  Is it because I don't have experience in relationships so I refuse to jump in?  That wouldn't make sense, I lack experience in many fields but I jumped in and learned.  I just don't get it, I just don't understand.

Addendum:  It's been about two hours since I initially wrote this.  I did a bit more digging and I realize that the time frame I think in is too long term.  I also realize that I'm too "formal" and too "professional".  I also believe that I need to make time for people.  I need to modify that.

Note to self:  Be more confident, eliminate shyness and indecisiveness.  Think short term, not long term and be more relaxed and casual, go with the flow.  Always make time for people.  Be more expressive of emotions and affection toward others.