Shopping is a thing/an activity that can let (this is a literal translation of 'rang' 让 and a common mistake) help/make you feel happy.

The pot have had broken before two days before/ago, so last night my roommate and I were going/went to the supermarket bought to buy a new one (place this time phrase 'last night' at the beginning of the clause) lastnight. During the shopping period/While shopping, we looked over all the pots and discussed their function, applicability and so on. At last we bought the one we both all agreed upon. Looking/Thinking back over the before shopping previous experiences, I felt really happy/happiest about shopping this thing, whatever buy no matter what things I buy. I love shopping.

I understood it all, but have suggested many changes.  What kind of pot?  Ceramic, Clay, Stainless steel?

Shopping is a thing that can make you happy.

The pot had broken two days before. Last night my roommate and I went going to the supermarket and bought a new one. During the While shopping period,we looked over all the pots and discussed the functions, applications and so on. At last, we bought the one on which we all both agreed. Looking back the to before the shopping experience, I am really happy about shopping this thing,wahtever and buying what things. I love shopping.

I hope I Kept the meaning you were intending. ????