help!

Hey i really need some advice! and im not sure where to start! ive a 3 year old girl day time potty trained and an 18month old boy..they both have been sleeping in the bed with me for over well im not sure any more! i had my daughter off her bottle and sleeping through the night in her own bed from about 14months but when my son came along and i was breastfeeding him he was in the bed with me a lot..then she ended up coming in because i think she felt left out..so they would both end up in the bed with me most nights so when he went on the bottle she wanted his and of course i gave in an gave it back to her,yes i know a huge mistake! i was working looking after the house and trying to juggle both kids as daddy wasnt really around and even when he was he ended up in the spare room because they ended up in bed with us..so my problem now is how to get them both off their bottles at night and how to get them out of the bed..and how to get her potty trained for night time! myself and their daddy have split up an ive been living in my parents house so they have still been in the bed with me..im moving into a house next week with them but i have no idea where to start..he has never really slept in his cot and they love to sleep together..i know i need to get them off the bottles at night but when i have tried before he especially would scream and scream untill he got milk then he would be fine..hard to ignore when he is in bed beside me! so now im not sure what to do ! do i put them in the same room in a bed together or in the same room in separate beds or in separate rooms..also my daughter is acting out a lot tantrums i dont know how to deal with she will not share and if she does not get her own way and believe me i do try not give in she kicks screams and everything inbetween! my mum says she dosent think its the terrible 3's but how do i get around it... id really appreciate any advice any one could give...thanks in advance xx