Looking for a few tips to help me with a project. I got a Trek 7.5 FX 2012 as a hand-me-down and love the bike, but I am having trouble getting used to the brakes. I would like to do a conversion to disc brakes but I have never done a project like this before. I am an apartment dweller and so this is the only bike I have for commuting so I also can not afford to have it out of commission for an extended period of time while I tinker with it. I am thinking I need a new fork, new front and back wheels, rotors, mechanical calipers, and a mounting system for the rear caliper on the frame. What parts specifically should I get and what advice should I listen to to avoid common pitfalls?
New fork, wheels and brakes is a significant art of the bike. You'd be better off selling the bike a buying a new one with disc brakes. Especially as the market for cheap MTBs or hybrids is exploding in the Washington DC region during the Corona pandemic. (Yes, I looked where you located, and that's where I live too)
Going the new bike route avoids screwing around with a rear disc brake converter and ensures you have a bike available at all times.
Alternatively, V-brakes really should be perfectly adequate and have sufficient stopping power and modulation for a road oriented hybrid. Have you considered having the brakes tuned, or perhaps upgrading the pads? Properly adjusted brakes and high end pads can make a great difference to braking performance.