This advice is all based on 3 personal experiences, so is not "expert" or anything, but you can give it a try.

When I get stuck in SP and can't seem to get out of it, but want to LD I do this:
1. repeat to myself "know I am dreaming" for a few minutes, then
2. stop focusing on the SP and anything else and just fall asleep.

Two out of three times I ended up having a LD (DILD) even though I'd "failed." Maybe you'll have similar luck?