A new fridge is probably a good idea, but as an interim measure, OP may want to get the current one serviced or cleaned. Those built-in ones often collect a whole bunch of gunk (dust, cooking grease, etc) on the coils. Also need to do the 'dollar bill' test on the gasket- it may be getting tired. The freon may have leaked down a tad, as well.
Of course, if OP has to pay someone to do that, it may be a significant fraction of the cost of a replacement. Standard logic about repair costs versus expected remaining lifespan, compared to replacement costs and increased energy efficency, apply.
aem sends...