1990 Chevy Cavalier Wondering what the problem could be?

1990 Chevy Cavalier 6 cyl Front Wheel Drive Automatic ALOT miles

Hi, I have a 1990 chevy Cavalier, for the most part we have not had much trouble with her. But just the other day when I put the car in gear she was making a loud noise, smelled bad and when driving I could feel a virbration. Later that day me and my boyfriend look under the car noticing that there were 3 holes in the exhaust, 1 befor the cat. And the other 2 after the cat. So. Would these holes be causeing all the problem listed above. Or is there maybe something else wrong?I do a lot of highway driving, is that good or bad?