Electrolux Refrigerator Not Cooling and making Clicking Sound

I brought this fridge (150 litres) around one & half years back. I was not at home since last 3 days. When I came back last night, I found that the fridge and freezer are not not at all cool. Everything kept inside the fridge was warm.

I tried unplugging and plugging it back but nothing worked out. Then I noticed a little click sound and then humming sound coming from lower back of the refrigerator, may be from the compressor. It keeps happening every 1-2 minutes. There was little dust. I cleaned it with a dry cloth. But again nothing good happened.

Now I have switched off the fridge. Please suggest me, what can be done? Should I call a repairman or it can be repaired by self?

Thanks for your time!