No power and has loud clanking noise from under the hood

I notice my SUV had a loud clanking noise when I put it in reverse so I got out to hear it while in park, that's when I heard the noise.After driving it a few miles, it lost power so I coasted it into a parking lot and turned it off and after a minute or so, tried starting it up and it started with no problem but would only drive with very low power. I was able to get it home less than a mile away. That was on Monday. Tuesday I went out to start it many times with no problem and it would go into reverse and go forward to my parking space. Always have the loud clanking noise and spent more time listening to it and the noise is coming from under the hood on the right side. I tried driving it one mile and it won't go over 15 mph. Please help! This was bought in February this year and came with a check engine light on. The oil has been changed, the air filter too. The A/C wasn't working and it was fixed. What could this be?