White belt, 125 lbs, competing in 2 months — how should I prepare when everyone in comp class is much bigger and more experienced?

Hey everyone,
I’m a white belt at 125 lbs and I’m competing at the IBJJF Lisbon Open in about two months.
My problem is that almost everyone in our competition group is around 176 lbs (80 kg) or heavier, and they’re much more experienced than me. Most of them are purple belts or higher.
Against them, I struggle to execute my game plan at all. Most of the time I’m just trying to survive, and I’m finding it difficult to tell if I’m actually improving or developing my own game.
At the same time, I can submit pretty much everyone in the beginner group, so that training doesn’t feel very challenging anymore.
We also have an advanced class, but around 90% of the people who regularly attend advanced training also attend the competition training. So there isn’t really a middle ground where I can consistently train with people who are better than beginners but still somewhat close to my size or experience level.
Another issue is that during our competition/advanced training, we mostly drill heel hooks, kneebars and toe holds. Obviously, I can’t use those techniques in my upcoming IBJJF competition, so I’m not sure how much of that training is actually helping me prepare for the ruleset I’ll be competing under.

How should I prepare properly for the next two months?