If he gets an erection the minute he tries to penetrate me he loses it. I have also performed oral sex on him and he is still unable to. Can you help us? He is going to a Dr. And they have talked about Viagra but there are tests he needs to go through first. I have also read up on Viagra and know there can be serious side effects. I don't want to do anything that will hurt him. Is there another solution?

At his age the answer may be Viagra, or one of the other drugs, or it may just be psychological. If he worries that he can’t maintain his erection, then those worries can make it impossible for him to do so. Since you two were having some problems with intercourse, he might have felt increased pressure to perform, and the stress from that pressure is causing him to lose his ability to have erections. So even before he hears back about the tests, the two of you should try to have sex a few more times but in as relaxed a manner as possible. Just look at it as an experiment so that he won’t feel too much pressure. I’ve not read that there are any really serious side effects to Viagra, so if that ends up being the answer, I think that would be OK (but I’m not a medical doctor so you might want to ask his doctor more questions.) But either way, try to see whether by keeping stress to a minimum when having sex won’t help him to both obtain and maintain an erection long enough to allow for intercourse.