Help my doctors making me feel like a lab rat (someone just to use to test out drugs etc)?

i went to doctors 7 months ago because i was suffering with anxiety he said i was depressed and put me on 20mg of citalopram which went up to 40mg of citalopram this didnt work so he put me on 20mg of prazac and sent me to a psychiatrist who said i have borderline perosnality disorder and told my doctor to put me on a different medication olanzapine and said i will need my blood checked and ecgs to check on my heart after all this im starting to feel like some sort of lab rat i only went there for anxiety and now they are making me go threw all this i dont want them to start poking needles in me and messing around with my organs (as he said it could mess with my heart) now i dont no what to do and its really starting to stress me out but im also worryed that if i dont go along with it then they wont help me at all. and also im wondering if i refuse the blood test will they not help me (as im petrified of needles) any help would be much appreciated