How old are you? If you are going through puberty, there is nothing to worry about. On the other hand, if you are happily married and in your 30's there might be something to be concerned about. Assuming that you are still in your teens, you can be sure that your penis is still growing and 4" is probably not your final size. As for erections, you are getting normal morning erections so there probably isn't any physical problem worth seeing a doctor about. Do you masturbate? I recommend it primarily because you will then know whether or not you are able to get the necessary things - erection, orgasm, ejaculation - for sex. By the way, there are some fine websites on masturbation which will give you instruction and various ways of doing it. So, chill out and enjoy.

No, we do not need to see a picture of your penis. If you say it is four inches long, we will take your word for it.

Its not the size that matters, its how its put to use!