User: My dick can't get hard anymore. How can I enjoy sex anyway?
Assistant: Yes, that sounds serious. This question might be outside my realm of expertise. I can tell you this: the Internet is full of information about this, so you can go look for yourself. However, I can summarize for you what I know about erections.  First of all, it's natural to have erections at night, for instance, during REM sleep.  An erection might mean that the body is repairing itself during sleep, that's all.  If it lasts more than 30 seconds, you might be experiencing an arousal dream.  If it lasts more than three hours, though, that's not natural, and a trip to the hospital is probably a good idea.  As far as enjoying sex without an erection, you could find some porn on the Internet that turns you on, and practice on your own.  That said, you might be dealing with some complicated emotions, and there are professional therapists out there who might be able to help.