Believe it or not, this is typical of when the rope is used to 'brute force' get yourself out. I have exhausted myself doing it and even if it works (it does if you're persistent) it tires you out. Just relax yourself much more in the beginning of your routine when you're still focused on the physical body, and after you're in a decent trance you should feel lighter (although don't focus on feeling) and it should work easier.