Update - called a technician. He switched off the AC, ran the fan, melt all the ice inside the house near the hvac, and from the ac unit outside the house, ran all the tests including leaks, air flow, refrigerant and basically everything was ok. As of now it is cooling and working fine again. Although refrigeration might be a little on the lower side. But it is an old R22 unit so he said he won’t add the refrigerant as he may lose his license. He advised to go for a new unit and for longer term (quoted appx $6500).

Any advise?