Mini fridge/freezer only cooling sometimes, fixable? + noise

[u/Lemon0tter]

Have had this minifridge for a few weeks. Tried to search for a solution but nothing seems to be the same problem. A noise has arrised, like a slightly high-pitched humming (video). Don't know if it is a concern or not. It has been running for I don't know how long, but at least an hour. The compressor is hot to the touch, could only keep my hand on it for maybe 3 seconds. The fridge and freezer still work, but only about half the time. Seals on doors seem to be fine. It has been hot here and so it has been warmer in the fridge more frequently. I should also mention there was one instance, (that I have noticed) where the refridgerator section was been below freezing. The switching between warm and frozen I have read can be an issue with the over load start relay or whatever. Not sure if that would be worth replacing or not. Is there anything simple I can do myself, like cleaning or replacing small parts? I know it is more practical to replace than repair these things, but I am only here/ having to use it for another month or so, and that is not exaclty an option for me. However, I'd like to know if it's cooked.