Tablet & mobile version of my site is super laggy, interactions are buggy/broken

Hi all– I’m hoping to launch this project next week, so this is urgent!
Everything is looking fine on Desktop, but the tablet and mobile version of my site is extremely slow, the interactions are lagging and feel broken.
Specifically– the slider is very delayed loading the next photo, the hover/tap interaction on the white frames is delayed; preloading animation (mostly on tablet) is delayed and the counterUp code that changes the percentage number only works sometimes; the Early Access modal is extremely slow to load.
I ran a page speed test on it with Chrome Dev Tools and the performance is really low. I’m assuming that these issues are related, but I don’t know enough about software development to work out what I can do to improve the site. I’ve been decreasing my file sizes and trying to reduce site bloat but nothing seems to be working. (BTW, I tested replacing the main slider images with extremely light 100B svgs to see if the issue was related to how heavy those images are, and nothing changed).

(I have a lot of custom code, so if you’re checking it out be sure to peek in the page settings and embed elements)

Here is my site read-only link