I train BJJ 3 times a week at best (due to work/college commitments). I had some issues at training but the simple solution of training more improved this weakness

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I'm working out my diet which I understand is vital to weight loss. Maybe it is due to my body getting more used to grappling but I've noticed my initial weight loss has stopped and although I haven't made any changes to my diet - I'm getting heavier.
I want to add a workout to improve my cardio and ideally lose 14 lbs. I've always struggled to go jogging and I have never had a passion for weightlifting but at our gym we sometimes to a grappler based cardio workout - which I enjoy.
My question is, if I continue to train three times a week, monitor/reduce my diet and implement a cardio workout would this help me lose weight or would I need to turn the tempo up even more and add some HIIT using running?
Thanks in advance - I rarely post in this forum and hope my fat ass hasn't asked the most "n00b" like of questions.
Also, because of my time constraints a home workout like this was the kind of circuit training I like the look of:
YouTube - High Intensity Interval Training