B.B.
Some kids play by them selves and others need outside in put. My Oldest could play by herself... My middle (4) does ok, but does at times when I am most busy think he needs mommy to play. But he also has our youngest (19 mo)to bounce things off of... (literally). :-) The interactive play between siblings will make it easier on you, but that won't happen for a little while yet... And when it does it will be punctuated with ouches, screams and mommy telling them over and over to keep their hands, feet, bodies off of each other.
I also am a stay at home mom and find it easier for me if I just sit, play and then try to pick up where I left off... Maybe thats why I only get things done in 5 minute spurts... But they do get done... eventually.
At his age time doesn't matter... just what I want to do NOW.
Think about your day. Is there a time that you try to get lots done? Involve him... Instead of sending him to play trains while you clean the kitchen... Hand him a swiffer mop and let him clean with you. :-)Yes, the swiffer will spend half the time in the air. Give him a squirt bottle of water and a paper towel and ask him to wash the table... Just something that he can feel close to you and you can get your stuff done. When doing laundy I give my guys a stack of wash clothes and ask them to fold them.... Keeps them busy and is easy to clean up when they get bored with it...
Try many things...
When you do feel angry or impatient stop yourself and breathe. Every mom feels like that sometimes. If you do yell, go to him and tell him that you are feeling stressed out and you need mommy time to finish something. He understands more than you think he does... But give reasons instead of just saying "something to do"...
Personally I have had to rethink my prioritys... What is more important... Happy kids/sane mommy or no toys on the floor... If they do dump the toys out... at least its occupying them. :-)
Good luck and hug the kiddos...