roper frig not cooling

Purchased this Roper refrigerator from Lowes 3 years ago although the mfg date says 03-01. It recently just quit cooling and I can feel air coming from the freezer area when plugged in it is not cool and does not cool the unit at all.
There is a small switch (from a diagram either a relay start switch or overload switch) that will work when first plugged in but quit within 15 seconds or so. It’s located behind and attached to the (black round unit) compressor? or whatever that is. Is it something simple or is it even worth fixing?

We use had the freezer portion packed full of food and use the frig section for keeping pop and beer cool if this information helps thought I’d mention.
Thanks I look forward to your reply.
Mike