I hate to say it but nutrition is key. You can't drive a car without the proper fuel...you can't build muscle for the same reasons.

I think you could. The saying is "bodies are built in the kitchen". Power lifting isn't as strict. Look at Mark Henry, strongest man in the world. Not cut up at all.

if all you care about is being strong and not looks then eat everything in site and lift heavy.

you cant outsmart a good body. Nutrition is the key to a lean body, and without it you wont grow the proper muscle you want. Consistency and determination is all you need. Try adopting good foods slowly and try them even if you don't like them. Your best bet is to try to eat more protein and healthy fats such as a chicken (protein) and avocado (healthy fats). Slwoly add in the fruits and vegetables to suit it in. It will take some time, but you will get there. Good luck.