how to make a buck converter
The inductor current does not look strange to me, just the ripple is indeed rather high. But that is simply because the inductor is too low for the output current and the switching frequency you are running at. Inductor current ripple should be kept at about 30% of the nominal output current, although this is not a requirement. You just need to make sure the ripple current of the output cap is not exceeded and the inductor does not overheat. Also, you will probably need lower ESR output caps, to keep the voltage ripple within spec.
I think in your case it is more than 30%, but again, this should not be a problem, just check the items I mentioned.
The error amp voltage seems to show some ripple, but it does not look like oscillation to me, since it is at the switching frequency. What I suspect is that the layout is not done properly and somehow you are picking up some voltage spikes generated by transistor drain current.
But it can also be, more likely, generated by the gate drive current, which is normal, since the gate current also goes through the sense resistor. And peak gate currents are short, but of high amplitude, so the voltage due to them can be seen across the sense resistor.
To check that, connect one channel of the scope to the gate of the transistor and the other at the Vsense+Vramp. Check if the falling edge of the gate drive signal coincides with the negative-going spike right at the top of the Vsense+Vramp. If it does, then you are simply seeing the gate current as the transistor is being turned off, which is normal.
The ripple at the Vea output seems strange, given that your loop is much slower than the switching frequency, therefore, I wonder if it's not a a case of improper grounding, or improper measurement. That ripple looks much like the output ripple, which would indicate that the error amp is not properly compensated, which I find hard to believe, since it seems stable, or it could be that the ground point was not chosen properly. I mean, even the scope probe ground may have been connected to the wrong point. When you are measuring the error amp output, make sure the GND of the probe is near the error amp ground, not some point where you have power components connected to.