CoreanBigSis said exactly right. But I would like to give you a bit different opinion. Firstly, The expressions ended by '~쪄' is mimicked babies say. '~ㅇ'-including expression could be used in the reality , as CoreanBigSis already mentioned. But,In my humble opinion, Those expressions are normally used on the internet. The origin was on chat or email. Hope this helped more.

well..This is actually not baby talk. It could be said talking like a baby talk for girls. We can say these expressions are for girls who want to show their love or affection in cute way to their boyfriends or sometimes for their friends(specially these are very comman and popular way in Asian culture). But if you use these too often, they could think you are too much. Especially if you use any boy you know, they might think you are cheap or easy. Depends on situation and person who you are with. And your expressions above are not quite alright. For example, we don't usually use 미안해잉(미안행 is correct), 잘했어잉(잘했엉 is correct), 사랑해잉(사랑행 is correct) those are dialect somehow. It could be ok to use but sounds funny because they are dialect which sounds like countryside people. Hope it helps you.