Honda Fit Sport 2009

When driving today, I was accelerating up a little hump out of a driveway and the car made a grinding sound and wouldn’t accelerate. I was able to put the car in reverse to a more flat area, and when putting it in park it made a grinding/buzzing noise. I turned the car off, got out, checked underneath the hood and under the car and there were no fluids leaking, no smoking/heat, or anything hanging. Turned the car over to just the battery, no warning lights appeared at all. Started the car without a hitch, shifted to drive and could not accelerate, then shifted back to park and the sound happened again.

I’m really hoping it’s as simple as transmission fluid or possibly a spark plug, but it’s very unlikely. Could anyone possibly provide some other diagnostic information? I’m 99.9% sure it’s a transmission issue.