First and foremost, welcome to the site.
Sounds to me like there may be a short somewhere, but I'm no expert.
I would check out this site to compare your custom wiring with to see if it fits that scheme. It may help.
http://lighting.mbz.org
Have you checked out your grounds for the wiring, including stock wiring?
How is your alternator? is it overcharging perhaps?
You may want to entertain switching over to European headlights. With stock 55w bulbs, I am getting a better beam pattern and light output that makes the stock headlights seem like candles in comparison. all this With the same standard watt rating as the stock bulbs. Price is not too expensive, and an easy DIY project.
I hope some of this helps.
Alon