Asking for a little advice on the best way to layout a new network.

I designed a new network for our company's recent acquisition, but I'm starting to second guess what I settled on, so I was hoping you guys might be able to guide me to the best way to do what I need.

New building. 5 IDFs connected to the MDF with MM fiber.

My original plan involved keeping three physically separate networks across the 6 strand fiber, data/APs, voice, and cameras. Basically, each IDF would have three switches for each network, each switch back to the MDF, plug the fiber into the corresponding switch. From there, the data, voice, and camera switches were going to be patched into a "main" L3 switch so they can communicate with each other.

I'm beginning to doubt my concept. Should I just VLAN? If so, what's the best way to doing that with something of this scale?

Also, I'm completely stuck on the DHCP server setup. Should I just create two new scopes (voice and cameras) to add to the existing data scope? How do I ensure the right device, such as a phone, gets the proper IP from the DHCP server residing on the data network?

Thanks so much for the help. I'm feeling in way over my head here.