Hmm, unfortunately I think it just IS this hard and draining all the time. If you've always let them get away with it, then it's work to change those patterns.
At their ages, you ought to be able to use the family meeting technique, I think it would work well. Essentially get everyone to sit down together. Brief DH and agree on a shared approach first. But address everyone and say we're having this meeting to discuss how our family works.
Explain the problem: You end up doing too much and it's not fair. Everyone needs to learn to pull their weight.
Agree responsibilities for everyone - personal (homework, own room, etc) and general/joint (a rota system, a pool of tasks anyone can pick from, and routine aka when these will be done. Discussion is allowed.
Agree rights/privileges for everyone, probably based on age so that it's "fair". Discussion is allowed.
Agree consequences if responsibilities are not stuck to - most likely removal of privileges as aforementioned - BUT - let them contribute ideas. It can be surprising what they come up with. STICK TO THE CONSEQUENCES. (So make sure they are things you can enforce).
If you like you can add rewards e.g. if someone goes above and beyond their role.
Finally draw up a "contract" and get everyone to sign it. Agree to trial the new system for one month and then repeat the meeting. I think you will have results within that one month and totally transformed attitudes/life by 3 months.
Do you have a family tablet everyone can access? Get the app Tody and put that on it. Set up all recurring tasks by room and assign who is responsible for each, it will automatically rotate for you. I think it costs £5 a year, but it's totally worth it. (Then £5 extra per account if you decide to put it on other people's phones as well).