Hmmm....ok....
I do understand that you're not a serious fishkeeper, as we all are, but you do need to sort out your tank. The fish are relying on you to keep their environment healthy for them; they can't just up and leave like a cat!
First of all do some much larger water changes. Start off by doing 50% every day for the next week. Although your white clouds might well be 'gravid' (carrying eggs; they don't get pregnant as such), as they're a very easily bred fish, swollen belies can also be caused by a condition called 'dropsy' which is, ultimately, due to poor water quality.
A 30l tank could only properly support six or seven white clouds (although a lot of people would say they need a tank at least two feet in length as, even though they're small, they're very active swimmers), plus the shrimps, so long term you're going to have to either rehome some fish, or upgrade your tank to something bigger.
A two foot/60l would be just about acceptable, if you kept up your regular, weekly, water changes.