While I can't speak to the quality of the CS program at UMF, last year they cut 9 faculty positions due to enrollment being down. Those positions weren't in CS, but things do not look great for UMF.

I'm an introvert as well and would personally use this as an opportunity to grow by going to a bigger school with a more comprehensive program. There will be "growing pains" for you, no doubt, but a research university will definitely have more resources.