Now, for my question.  The other night I was so aroused that my breathing was heavy and my heart rate was fast.  I also felt like I was going to explode. The person here was willing to help me, and my parents were asleep.  I didn't masturbate though.  Is it dangerous NOT to masturbate if I have these symptoms?

As far as I know, and I am not a medical doctor and I know nothing of your exact condition, but there should be absolutely no danger in not masturbating. What should happen is that your arousal will naturally go down after a while and that would be the end of that. Men can suffer from what is called “blue balls” if they fail to have an ejaculation after becoming very excited for a certain period of time. But even that is not dangerous, only an uncomfortable feeling in their testicles for a while.
I am going to assume that you are under a doctor’s care. What I want you to do, the next time you see your doctor, is to ask to speak to him or her alone, without your parents or anyone else being in the room. I want you to ask your doctor to speak with your parents and explain to them that although you have many physical limitations, you still get sexually aroused and need to masturbate from time to time in order not to feel sexually frustrated. Now I’m not saying that your parents need to position you for masturbation, though if you could work that out, that would be fine, but you shouldn’t have to wait for them to be out of the house or asleep either. If there is somebody over who can help you and that person leaves while they are around, your parents  should know that they need to knock before entering the room. If there is someone else who could talk to your parents other than your doctor, like a sibling, aunt or friend, then that would be fine too. I’m sure you undergo plenty of frustration in your life, but being sexually frustrated to protect your parents from being aware that you have sexual feelings shouldn’t be a source of frustration.