What to do if i have a severe phobia of needles, how do i over come this?

There are a few: Techniques that can work fairly quickly. Cognitive behavioral therapy using progressive desensitization (learning to relax ; then imagining the phobic event from least to most anxiety provoking image while relaxed. I usually do this using hypnosis as a relaxation technique, but you can use other relaxation methods. Find a therapist ; you will be able to get relief fairly quickly.

CBT: Seek a cognitive-behavioral therapist who specializes in phobias. One method they use is systematic desensitization which slowly and incrementally brings the person closer and closer to the thing they are afraid of in slow, graduated steps that help make the anxiety more tolerable.