You sound tired already! I have one and she sleeps late too, 11 pm, wakes up 4 am, and back to bed until 9 or 10 am. The difference is she sleeps alone in crib.
Babies go through sleep cycles just likes us. When we wake we can make ourself fall asleep again (shift position, for example). Babies when they get up have to learn to self console and do the same. When they are in your bed with you, it makes it harder for them to self console. They see you and they cling on, and sometimes wake up again for good. Sleeping 11pm till 7 am is not enough, i think, for a one year old, btw.
So I think for the best interest of you (u need to be healthy to be functioning mummy), and for them (learning to self console in bed is good practice for them to later self console in life), you may need to do a sleep trainig session with them. It is so hard but it is worth it.
THere are so many sleep training books and methods out there and I find the one that worked for me was the one that let them cry and u keep checking in on them every 5 mins, increasing it to 10 and 20 mins with each night. You say the same thing to them everytime u see them (like, mommy here, go to sleep, u r ok...) but don't pick them out of crib. If 5 yr old gets out of room, put him back in room. Keep doing that (and it will be sleepless week for you and husband), and it will work. I have heard horror stories and see it work.
I don't think kids should be in bed with you even though we like all the cuddling :) That is just my opinion. I know others feel it is ok to have them sleep with you. But if you are now being too tired, then it is a problem.