Well first of all, its not a race.

Dont be afriad to take things as slow as you both need to.

If he isnt moving forward and you feel as if you are, then you can eaither comunicate with him and try to help or move on without him, or stop and wait for him to catch up.

Without knowing the specifics of your relationship its hard to give general advise that going to be directly aplicable.

You say you know he is frustrated...how? Does he think your being demanding> Does he simpley not know what to do or not do? Is he lacking in initiative, or has his intrest wained? Is it a matter of not having enough information, or...do you both need to learn effective relationship comunication skills? (which isnt nessesarally a bdsm thing per say)