In and out of trance

I seem to have trouble maintaining anything more than a light level of trance. I frequently and easily get to a point where my arms and legs feel heavy and numb, but not full paralysis. I find I get stuck at that level a lot.

When end I do get a little deeper, everything happens in a hurry. I either notice I'm heading deeper into trance and that noticing act brigs me back to a lighter level, or I fall fully asleep, The problem is, the transition to either is so quick and seemingly uncontrollable.

I do occasionally get to a deeper state while still maintaining some quite, consciousness.

Any suggestions on how to improve my ability to consistently get deeper into trance without vacillating back and forth into lighter states or going fully asleep?