Work/Mom/Wife Juggle

This whole work mom wife life juggle has been a lot harder than I expected. I know everyone struggles with finding a good balance but it's been really tough lately. I never imagined ever that I'd want to be a stay at home mom until now and we can't really afford for me to stay home so it's not really an option. I'm also the kind of person thats really bothered if I'm not being the best employee possible but I can't really do that anymore because if my baby needs me or is sick she obviously takes priority. I guess what I'm getting at is I constantly feel like I'm failing as a mom and an employee and kind of as a wife too. Like instead of being great at any of them I'm barely scraping by as mediocre and it's really getting to me..