Ok so all of sudden when I start my car it makes a screech noise for two secs and then comes the rough idle. Ive sort of always felt this rough idle when my car is trying to tell me its time for a tune up so I thought nothing of it. However, I put the car in drive and as I accelerate I hear my exhaust yelling at me. It sounds very loud and almost feels like its struggling to keep power. (Like a choking sound) Also, ive noticed a faint smell of gas or fumes. I believe its a leak in my exhaust. What do you guys think?

Btw, I had my muffler replaced a year ago but I dont think that is relative to this problem.
PLZ HELP IM TRYING TO AVOID SPENDING CASH FOR A CHECKUP