Short LDs from excitement are something that we all deal with, particularly starting out. It still happens to me, even though it's less often than at the beginning.

Since you are so strong with WILD, one option you have is to DEILD whenever this happens to you and just dive back into the dream. DEILD is really just a WILD but under even more ideal circumstances, so you can put those same skills to good use again!

The other half of the equation is building up your expectation that you will get lucid and then have some other specific goal in mind. Something to take your mind off of the extreme excitement and (sometimes) surprise that you've achieved lucidity. You know how you hit your nap WILDs 80% of the time? Remember that. It means that when you become lucid, you are exactly where you expected to be. Now simply acknowledge it and anchor yourself into the dream scene.

I like having something very specific to do. If you are having trouble slipping out, consider having the goal of rubbing your hands together and just getting really, really into the detail of the dream scene. Make it your mission to appreciate the incredible detail your mind can produce for you. Check out all of the scenery in the dream with every sense. If you have not had the chance to do this, it is a mind-blowing experience. My 2nd LD was a series of experiments along these lines and I still think about the results with a sense of wonder.

You are doing great!! Keep it up.