What can i do to stop my fear of getting ill as its starting to ruin my life as i'm eating/drinking less because it might be contaminated with something or i just cant be bothered to stress over it so i would rather go hungry?

It would be best to consult with a therapist who can talk you through this difficult time. No need to live in fear.

Your psychological conflicts can be handled and you can learn coping styles which will create calmness and stabilization. Might start with a psychiatric consultation, and consider initially at least, employing medication. Would highly urge counseling with a cognitive-behavioral therapist. Learning meditation and adding biofeedback therapy would add value.