@brooklyngirl is 100% right Charris. Actually though, need to start more hydration 4-6 hrs before the draw. Its from what's called "roll over veins". I have them too and my personal record is SEVEN sticks! The poor young Women attempting to withdraw my blood was crying, she was SOO upset. I was trying to calm her down with a little light humor and kindly asked her to go get the "Head Vampira" to get my blood. They brought in some sassy old lady that got it in the first stick. I finally calmed her down and we all had a good laugh over it. BUT....even slight dehydration makes those roll over veins a lot worse. Also, don't take any allergy medicines, histamines etc before you go because that will increase dehydration and raise your blood pressure, that makes em roll over too.
Best wishes and luck to you, I know you've been through a lot, but you're keeping your focus and that's the most important thing!