The up and down of single parenting

Today was a down, I was trying to clean up my house and both of my son keep me busy.  So I ask their father who was not working today, he said he was going to be in the area so he will call. I waited until about 5 pm and called, he reply that he phone was not with him.  Which is weird because he was suppose to call me not the other way around and if not he know I was going to be home.  By now the 2 year old he driving me up the wall,  instead of clean I am prevent my son from hurt himself,  his brother or just be still.  So their dad said so I will pick up the 2 years old and I am on my way so it was 8 pm so I called not answer.   Then I called at 9 pm, "Oh I was not able to make it", really do he reality that this is his sons not his nephew or godchildren.  I am very upset because I do not ask a lot from him.  It have been over 2 weeks since he seen them and he lives only 20 minutes away.  I have to go outside when they was crying for 5 minutes to breathe and pray for strength.  Any other day I would be able to deal with this but today just got the best of me.  I try very hard to be positive but I was very upset that their father was not helping me out.  I was not asking for too much just a few hours to get the house clean, not me going out or something.  I just do not understand man as if they forget that they are also responsiblity for their children even if they are with mother.