Hi Ian -
If you want to go to college, you can major in biomedical engineering. This kind of engineer focuses on products and services for the health community. Many students major in biomedical engineering, or bioengineering before applying to medical school.
If you don't want to do engineering, nursing is an option and though this is work with people as you get older you will learn to deal with your anxiety, I also am anxious in working with people. There are many careers in nursing some deal much less with people than others. There is also an option to be a radiologist technician, this helps in taking MRI and X ray images and manage those images etc. You can start working in that field with a 2 year degree.
Hope this Helps!