Wow, that sounds pretty serious. Perhaps you should just check with the doctor again to be sure everything is ok. Nevertheless, what kind of saddle are you riding with and how level is it and how hard is the seating area?

I suspect your current riding position may be restricting the flow of some liquid (blood or what not) around your waist/hips area. Perhaps you need to adjust the seat angle a tad, nose down a bit, not so much that you feel like you are sliding forward or having to hold yourself up with your arms, but just enough to open your up a bit. Alternatively, if your seating position is right, raising your handle bar height may also ease congestion in your pubic area. Small modifications may encourage a little more blood flow in and out of the area. Either way I would be trying a combination of things to get this sorted out.

I currently ride a Brooks B17 leather seat. The leather has molded to the shape of my sit bones and riding position. It is now very comfortable, especially when in the saddle for 10+ hr, however during the break in period the seat was very hard. This type of seat may help with your problem as it will shape and adjust to your body, rather than forcing your body to adjust to a firmer plastic seat.

Good luck,

Donnie