Click on Wiki at the top of this page, enter Potomac TRACON in the search box and that'll take care of half of what you need. All the Potomac TRACON freqs are there - both VHF and UHF - and they are broken down by airport area.
For Patuxent freqs, go to the Maryland forum, click on the thread "Sticky Thread for MilAir II" and scroll down through the messages. I recently posted all the Patuxent freqs (along with Giant Killer, etc) as part of a series of posting all my MilAir bank frequencies to that thread.