2003 Ford Escape Shaking

My car randomly started to shudder/shaking while accelerating. It started out between 35 - 45 MPH and now its doing it from 25 - 45 MPH. It gets worse while traveling uphill. The vibration will normally only last for 10 seconds or so. And when I mean shaking, literally the whole entire car will shake. I feel it most in my center console and seat. Not the steering wheel. I've checked the obvious things, tranny fluid, air filter, intake hoses, throttle body, air flow sensor, transaxle fluid (black and smells like cat piss). I've checked the boots on the CV joints, I've changed the front tires, I've checked motor mounts and tranny mounts. And none of them are the cause of my problem. I can't think of anything else that could cause this. Ans FYI it literally just happened out of the blue, the car never had any problems up until this past week or so. I don't have money to take it to a mechanic. So I'm sorta at a loss. Any information would help.