Am I overacting

sometimes it is good to get others opinions...Do you think that I am overacting and should just go with the flow....my partner has been working away for about 1 year, with some short weekend visits, he bought his own house and moved out of mine apparantly needed a break, now has gone on overseas holiday for several weeks. He keeps getting angry with me over very small things and blames me for everything that goes wrong, he says I wont try and understand, and that it is me that is causing problems. He also gets upset with my children from a previous relationship because they dont ask after him when he is away I keep telling him that he has to be around to gain any committment from the kids, but he seems to think that they are just selfish...When he is here I love him to bits, we laugh have fun and have a good relationship. He is just away so often that I just get on with my life. Should I be more understanding, I know I pick fights unnecessarily and seem to take things to heart but he is never here..

Should I just go with the flow and let him get it out of his system. Or am I right and he just wants his cake and to eat it to. I am thinking of saying to him, that I am OK with a part time relationship for fun without committment, but he needs to stay out of my family relationships, he cannot have it all.