Topic: Stuck towards the end of Final Fantasy 8

I am having trouble beating Fujin and Raijin at the end of disc 3 in Lunatic Pandora. I’m worried I might have messed up my whole file because throughout the whole game I didn’t fully understand the junction and just spammed GFs in battles. I think three of my characters are in level 30s and two of them still around level 15. I have a feeling the boss battles after this will be even more difficult. In FF7 and FF9 I also had trouble towards the end but grinded for a while and beat the games. In FF8 since enemies level up with you I don’t know what’s the best way to get stronger to beat the later bosses. It doesn’t help the enemies don’t wait for you to decide on attack or magic and make me rush in picking battle commands. I admit I am pretty bad at this game and played it for the story experience but don’t want to use invincibility cheat either. Should I grind like in the other FF games to get past the later bosses? I would appreciate any feedback on this from FF veterans.