I think I quite understand your plight of been the only one performing a particular role. It gets really exhausting and tiring. Good you have already made your complain. As it stands there is nothing you can do about it has it beyond your hand. Having told your superior, it is best you wait upon them. You need to also remind them from time to time.
I would have suggested you let in someone on how the job is done but others seem to be also busy performing their own daily work activities too. Guess you will just have do time job when it is most convenient for you. Good you even have the work from home option. I believe at some point someone will be asked to help you when they see how the stressed the work must have on you.