I'd post this also on the Men's forum.

But one thing that strikes me is that you may have soap residue in your wash... and it is irritating the sensitive area you describe.

Tide makes a new sensitive soap now:
http://www.tide.com/en-US/product/tide-free.jspx

Also fabric softeners can be irritating too.

Just do a second rinse on a load of your underwear, and see
how much soap comes out the second time! For this reason we double rinse all our clothes now! Soap is very alkaline and our skin is acidic. Elevated pH to alkaline then becomes very painful.

I'd make sure ALL environmental things are excluded before going further medically. Even the soap you shower with.
You know women get irritated by soap in showers too... and don't realize that shampoos end up down there, and conditioners (and often are not rinsed off enough). (conditioners are surfactants and defat the skin making it very vulnerable to the environment).

If you can find some A and D cream, you might try using that on the tip carefully. It is typically in the baby section of stores. It is very healing and often helps personal discomforts and might work for you.