They didn't do any extensive testing, they said he had extremely low T levels and told him to give himself a shot of testosterone once a week. However, he has ben passing blood (possible ulcerative colitis) and complains of chest pain. He does seem exhausted, he goes to bed at 8 every night.
Yikes! This needs to be properly investigated, ASAP.
I find orthomolecular doctors to be far more thorough when checking health issues.
HERE is a list of many of them. They are regular medical doctors with an added interest in things like vitamin therapy.
But then on the other side he has had plenty of energy to go on these random mood swings when he is awake. He will go from fine to flipping out in a matter of seconds.
Health issues can cause seemingly opposing reactions at different times. For instance, he could be fatigued due to his poor health, but then get a burst of adrenaline from a reaction to something that's going on in his body (pain, low blood sugar, etc.) and then flip out with moods and be seemingly high energy. Then he'll crash after that wears off. That's just an example, but things like this are common with certain health problems.
You're both going through a tough time with this, but please support him. He won't want to be a burden on you, because he's your husband, so this could cause you both to withdraw from each other if you aren't understanding. If you can support him he will most likely open up to you and you will both be stronger afterwards.
Keep an eye on the big picture. This might be a temporary glitch in your relationship that brings you closer together after you have gotten through it.