You are not alone! I have ds1 who is 2.9 yo and up more than ds2 who is 13 weeks old. He actually manages to wake up ds2 shouting from a different room (not on purpose) which is so frustrating.
I cope by : going out lots, especially with friends who have dc ds's age, and can grab a baby/ toddler as needed;
Toddler groups just starting up so another place to go;
Having very low house work standards and a cleaner (who even did some washing for me last week 
);
Not ironing anything, ever;
Accepting sometimes I look a fright in the supermarket, and getting shopping on line most of the rest of the time;
Insisting if ds1 won't have a nap then he has quiet time on the sofa with pillow and blanket (and yes tv); not feeling guilty about Cbeebies - it is currently my friend;
And remembering that this is a phase like all the others and it will get easier.
But, just once, I wish they'd both sleep at the same bloody time!
It's hard, isn't it.