Hi Willuwont - glad to hear you've been enjoying the game!
If you're running into more than one tiny tentacles (the little shroom that generates shields) it means you let one escape from your previous combat. If I can offer some advice for future runs, it's a pretty solid strategy to always focus your attacks and debuffs on Tiny Tentacles first, take them out before they can generate too many shields and always be sure to prevent them from fleeing. Good luck on future adventures!