In my opinion the problem here is with your transitioning. By the sounds of it, you don't have much problem opening and being yourself, which is great! Opening is the hardest part of the conversation for many people. You need to transition to a different conversation before they get bored though. It could be anything...
When I run out of material I usually resort to jewelry. I know quite a bit about rings, so I usually go with that is an interesting ring! Can I see it? This gets kino going cuz she should give you her hand. What does it mean? I then sometimes do a magic trick with the ring or run the ring routine to DHV myself etc... You could use anything of interest, just make sure you transition before convo dies out. Just practice and it will become natural. Good luck and keep up the good work!
