I have DD1, 24 months, and DD2, 7 weeks so I really know where you're coming from. Just remember that IT WILL GET EASIER!!!!!
If they both want breakfast at the same time, I deal with DD1 first.....it only takes a few seconds to put some ceral and milk into a bowl, whereas a breast feed takes us 40 minutes. I then sit at the table next to DD1 whilst she eats her breakfast, with DD2 on the boob.
Lunch...DD1 has something really simple that I can make quickly (a sandwich or beans on toast). Dinner......she has a home cooked meal that has been cooked in advance and frozen. That way all I have to do is take a tuppaware box out of the freezer and bung it in the microwave for 5 minutes. Although the other week I did manage to make and serve fishfingers, peas and mashed potato all without taking DD2 off the boob!
Bed/bath......don't do it!!! My DH has had to do bed time by himself pretty much every night since DD1 has been born. She doesn't mind at all cos she hasn't seen Daddy all day so it's a good chance for them to spend some extra time together.
I did feel very guilty at the begining because DD1 no longer gets the same level of 1-to-1 attention that she was used to (I am a SAHM) but she loves her baby sister.......she helps me change nappies, sits next to me to read a book or watch cbeebies when I am feeding, and even helps me to burp the baby! She loves to be involved and help mummy. I also know that DD2 is not going to have the same level of quality mummy time that DD2 had as an only child for 23 months, but also know that DD2 doesn't know any different! I also remind myself that DD1 will go to nursery this time next year and then DD2 will get to spend lots more time 1-to-1 with me.
Take all the help you can get and keep reminding yourself that IT WILL GET BETTER!!!