Kids drives me crazy !!!?? Help

So i have a 6 year old who cries ALL DAMN DAY about EVERYTHING And i have a 2 year old who does not sleep but cry when she wakes up. She do NOT stay sleep! And i tried putting her to sleep with my oldest daughter. But anyway i just feel so frustrating because all i do is yell and I’m tired of that. I take away my iPad and she can’t get on my game etc until i say so. (When she’s in trouble) and She cries about that but she knows I’m not playing with her. Now she just wakes up mad because she can’t get her way so she cries now i gotta yell because she’s irritating me with the crying. I literally trying every thing like walking out the room ignoring her and just you know giving myself some space. I don’t know what to do it’s frustrating and I’m tired of yelling everyday all day.