Hi bud,
Cant assume its down to your anaerobic system, without looking into it fully couldn't tell you for sure. It could be, but it could also be that your aerobic system is not specifically developed, or you don't have the muscular endurance in specific muscles.
You need a well developed aerobic system, no question. To get this you can use longer duration non specific modalities such as rowing and do the session outlined above, or some 1k rows with a minutes rest or so. Always good to have something to work towards to times, distances etc.
Or you can work more specific endurance which would be your MMA circuits with ropes, sledgehammers etc in there as well as heavy bag work etc. Then obviously the most specific is sparring which will certainly condition your lungs provided the intensity is fairly high.
Anaerobic intervals would be much longer rest, like 30-40s of work at max intensity with 2-3 minutes rest.
So to answer your question I would say that you need more MMA drilling and sparring and specific circuits as you may be well developed aerobically but not specifically for MMA.
For the MMA specific circuits throw in anything that you feel you need to work on so if its stand-up stuff use heavy bags punches, skipping etc, ground work do GNP, total body lifts, or if its a combination then put it all together.
Work:Rest negatives are good for developing both aerobic and anaerobic and to be honest unless you have been tested and found to be poorly developed in a particular energy system this would be the method i'd use. So tabatas like 20s work:10s rest x 10 reps should be the goal, but depending on your condition you might have to go something like 3 weeks 20s Work: 40s Rest, 3 weeks 30:30, 3 weeks 20:20 then hit the 20:10.
You want the work you're doing to be quality in that time not just mincing about absolutely ruined!
I put a piece together on it a while ago you might get something from I think from memory there's a progression in there too:
Combining Strength and Endurance Training
Hope that helps :)