I'm sorry you have spent any time worrying about this. If you are not having inappropriate sexual contact with your child, your child will never get herpes from you.
Yes, it's possible that you could touch a sore and then touch your mouth or eye and infect that area, but that is usually only possible with a new infection before you have antibodies to protect yourself from this.
It won't transmit to anyone else like this. If you touch a sore, by the time you'd touch anyone else, you'd probably be non-infectious, given exposure to air, touching other things, etc. The only areas of the body that you'd need to be concerned anyway with are mucus membranes - eyes, nose, mouth and genitals. Even if your child picked up your underwear, the skin on their hands is too thick for the virus to penetrate.
I'm not sure what you mean by water "going through" your penis, but if you mean that the water in the shower touches your body before it hits the bottom of the shower/tub, and then your child touches something that is in that shower, that's fine, too.
But really, herpes isn't that easy to transmit during sex, much less with casual household contact. You are only infectious from your genitals - that's it, and it takes direct skin-to-skin genital contact with some friction for you to transmit it to anyone.
You aren't a walking bio-hazard or walking, talking infection. You aren't infectious all the time. Millions and millions and millions of people have herpes and a large portion of them have children and they all raise them normally.
I hope this helps and allows you to take a breath and not worry so much. Don't have inappropriate sexual contact with your kid, and you'll both be fine. :)
Herpes lives in the nervous system. This means that you worrying about it will make it more active so ironically, worrying too much increases the opportunity for transmission. Your child has to have a cut or abrasion for herpes to get in. The reason why it is often sexually transmitted is simply because mucous membranes are more delicate than ordinary skin and so get damaged, cut or abraded more easily. Herpes CAN live on surfaces under the right conditions for some time, but the odds of actual transmission by this method are extremely low. If your child has an open wound, bandage it up. Humans have immune systems and are able to overcome even herpes virus in very small quantities without getting infected so if you practice common sense, I don't think you have anything to worry about.