Family Crisis gave another child

My husband and only son were in a terrible car accident, my husband died at the scene. My son than 18 was badly injured and in a coma for four months. It looked like he had some brain injury, but the specialists said he could recover in time. We were financially well before and still were after the accident. I didn't need to work so concentrated on getting my son better. Two years after the accident we were living together in the same apartment as before the accident. My so could walk and was slow in his reactions, he seemed retarded. But the specialist said it would dissipate over time but couldn't tell how much time. He just needed something to stimulate his recovery. What he couldn't say, one day he had a fall, and I heard a crashing sound rushed to see what had happened. I'd been in the shower, didn't stop to dress or cover myself. I found my so uninjured and help him into a chair. He was okay and the only thing I noticed was a bulge in his pants. First time he'd gotten a hard-on since the accident; I don't about before the accident if he'd or not. I realized my naked body had stimulated his brain, a good sign if somewhat unexpected. I decided to return to my shower and take my son with me; I was going to get him off and see if he improved any because of it. He did improve somewhat he was more attentive to me over the next few days. So. I decided to shower again with him and take care of his hard-on if it arose, it did. Several more showers and he had started responding more. Then one night I was in my bed, and my son came and joined me in my bed. At first, he just cuddled up to me, then he started touching me and fondling my breasts and then he put his hand inside my panties. At first, I was shocked and was about to tell him to stop doing that. But decided not to, as he was highly stimulated and each time, he was stimulated he improved more. I didn't expect him to try and mount me, but he did. I'd a choice stop him or let him, if I stopped him, he might regress and stop improving. If I let him fuck me, he might get much better. I hadn't had sex since before the accident, so I let him fuck me. Only later I realized I wasn't protected, but what the hell my son got better slightly quicker than before. He started sleeping with me every night thereafter. Not always fucking, but at least once a week I let him fuck me. He improved greatly almost back to how he was before the accident after six months of sleeping with me. Only one problem I was pregnant to my son, but he was much better and the baby was healthy. That's a plus in my book, passed the pregnancy off as my late husband's using his saved sperm. None was saved but only I know that, so it was just accepted as fact, reason for the delay I said was my son's health came first.