Not sure what you refer to as "normal soil"? You say it is wet but not soaked - is that wet on top? If so, it is probably too wet deeper down. Check with anything wooden/bamboo, sticking it deep inside of pot. Or just dump out the soil and spread it to dry it up.

Your plant looks like it is loosing roots to rot, and soft, falling off leaves are probably rotting too. It is worse if new leves are falling off, since the center is probably all rotten. Not really ood enough photos to be able to tell, just going by your descriptin.

Let it dry up, putting it on something absorbent helps. Cut off all dry and otherwise damaged roots, nd hope it will work. Plant may be re-rooted, but there need to be enough of healthy flesh.

Pot after drying into better potting mix: soil mixed with lots of sifted perlite - in 1:1 ratio - would be better draining.

BTW, saying it is cold again doesn't help - how cold? is plant inside or out? what is your growing zone/general location?...