Cut everything off for a few minutes then turn it back on and listen for a click from the compressor relay as the compressor tries to start. Is the compressor motor running.If no check starter/overload relay. The relay is a small usually black cube shaped electrical part plugged into the compressor or wired to it nearby. It may appear burnt or rattle when shaken if it's bad. The two connections should show continuity with an amp meter. If it's good then it's most likely the compressor causing the problem.
Bypass the cold control and see if it comes on. If it does then change the cold control if it dont then examine the compressor relay and see if it is burned up. If the compressor relay ain't it then you have a bad compressor.
If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61
If the unit is running continuously and not maintaining the temperature cold enough the system may have a leak. If it is NOT running continuously the problem could be in the temperature control.
Either way if you had the doors opened a lot, it should like you probably have frost build up preventing proper air flow. You'd need to pull everything out of the freezer and remove the lower back panel inside the freezer. If there is frost build up, you'll need to use a hair dryer to thaw all the frost out. The unit will continue to beep until the set temperature (0 and 38) are reached so that could take a while even after thawing out all the frost build up.
If removing panels sounds like more than you can handle, you can always unplug the unit for 24 hours and leave the doors open to allow the unit to defrost on it's own.
A Freezer usually has a condensor drain coming out of the compressor, that empties into a condensation dish underneeth, where condensation water is picked up and Re-evaporated.
It is most likely that your Drain is clogged.
Happened to me.
Have someone check your Drain, and if needed unclog it with a small prying tool into the tube.