PACING?! How to fix the issue?

I have issues when it comes to pacing the first act of my novels. I tend to move it along way too fast that by the time I get to the midpoint, I'm like "Wow, I'm only on chapter five??"

My second and third acts tend to be meatier, for lack of a better word. I'd love some tips or examples on how you all deal with pacing, especially in the first act of your WIPs.