100% sure you're dead blinded by love, yet nobody can blame you..(love can blind anybody)
having no parents(loving care), you desperately desired someone to love and to be loved and she became your angel.
After reading your post, it's too obvious that she's been *using* you.
There're many women who manipulate men to fill their lust and materialistic craving.(same with many guys, esp. lust)
It's(your post) a very typical case(girls using guys to get jewels&money). Women can charm guys easily.
I can't understand how she slept with over 40 guys and keeps doing it(U said she'd sex with her new 'toy' recently) even now. and brazens out, saying she loves you.(didn't say still, cuz I don't think she truly loved you ever)
and... (in general)buying her tons presents doesn't (usually)show your love at all, it only spoils her.
you really want to hold to the belief that she loves you, her words melt your heart. My guess is she decides to stay with you, so she can sponge off on you more and more and more.
You need to erase the 'love' feeling for a moment and COLDLY think about what's really been going on. Don't you see her pattern?
PS: want to say something to me, e-mail me.