Hi Doctor - My Son Is 19 Years Old And

Hi Doctor - my son is 19 years old and is having relationship problems with his first love. Physically, he has not eaten for 4 days. Every time he attempts to eat, he throws it back up. Nerves and all those things that go along with severe anxiety I'm sure are the cause. What can I do to help? He is a college runner and I will not permit him to run in this condition. I need to get nutrition in him. I'm struggling...