For lingerie, you could always search on Reddit for tall/plus sized lingerie. In fact, I searched that exact term and found one on the Plus Size subreddit. Another thing that I would recommend is having your measurements and looking at the measurements of the products if possible. Most online lingerie companies should also say what size their model is wearing and their measurements.

For clothing, that might be more of a challenge. I would still look online for plus sized tall clothing, I'm sure that you could find some information on Reddit or otherwise. There are specialty shops that do specialize in clothing specifically for drag queens, but I'm sure if you walked into a clothing shop (not a chain, most likely a boutique or other specialty store) they would be more than happy to assist you in giving fashion advice. I would suggest Torrid, Lane Bryant, or Maurices for stores that I know are around the states, although you might find more success at Maurices or Lane Bryant since you aren't short. Best of luck!