hey i swapped a gsr motor into my hatch about 2 months ago, pulled real hard for about a month and recently it seems like something is wrong with the car. like when im driving kind of slow, and i shift to 2nd, it seems like something underneath is loose or something, and when im in high RPMS and i shift fast it just doesn't feel like, it feels loose on the bottom of the car, could it be that my clutch is goin bad? i have a stock clutch btw

any help is appreaciated