I used to hate a lot fire mains too, then i got a full immune team and they ceased to be an issue (except for itachi susano'o, shisui, madara teams, but those are whales so, do not matter).

that said the reason why you arw losing is simply the fact you are using sasuke susano'o. Iruka would work way better.

P. S: Kushina habanero to work fine strictly requires a repulse to lowfloat chase, so you need or to run azure fang (and infact with azure fang she is way overpowered due to poison tai and healing tips) or shisui/edo roshi/kurama naruto/edo haku. If you do not use her with one of those 5 options you are running a very subpar team and obviously you lose against sbs with mirror and also against whoever runs pain ningendo or kurenai.