How do I get matts out of my dog?!

I've tried everything. Idk how they all of a sudden got this bad. I take care of my dogs well and she's the only one that gets them. She's a bischon frise 😣😣😣 I've tried brushing with a special brush while wet and dry, have tried using a dog grooming kit, tried cutting them out (don't wanna go that route cuz I'm scared I'll snip her.) idk what else to do. Any good ideas? And any ideas as to how she gets this way to begin with?! Is this normal with bischons?