At 5 months we didn't have a routine - but it did naturally begin to fall into place after 6 months as meals were introduced - I don't think you should worry about food in relation to milk feeds - honestly. Just start gently introducing solids and you will find that the milk falls off - I was just like you I got totally worried about all the logistics of swapping milk for food/ mealtimes/ routine....
basically somewhere along the way - you will find you have a toddler who eats three meals a day - it will be back and forth with milk/ food/ meals/ breastfeeds - there is no hard and fast path to get there....
I think one thing I would say though - of course everyone is right about relaxing - but if you would like more of a routine then that is okay too! I actually think I went so much with the flow that I hadn't realised how tiring htat was for me - fine for the baby , but with a little routine in the day you can vaguely plan to have a rest/ break yourself etc.
I recommend two things...firstly a book called the Millpond Sleep Clinic book - it is a laid back approach to routine that also really sorted out nighttime wakings.
If you want her to sleep well at night, she needs to know how to fall asleep without the boob. After a breastfeed, you will need to decide that is enough and get her back to sleep without more time on the breast - tough I know, but it really is worth it. Rock/ sing / cuddle etc - I went a slightly tougher route at about 7 months, of putting DS in the cot then patting him when he cried but not picking up - it worked very very quickly and there was not much crying.......he learnt to fall asleep in the cot on his own and stopped the frequent waking.
If you think about it from your babies point of view, she is falling asleep with a nice cosy boob in the mouth, but once its gone she wakes up and doesnt know how to settle herself.
All of this will be so much easier once she is on solids - I found sleep massively improved around 8 months - once DS was on three proper meals a day - then I felt able to stop the constant breastfeeding!
re. our routine - at 5 months I can't remember but surely wake up then a nap every couple of hours? I dont think many 5 months old sleep at the same time every day.
at 6 months DS started doing naps at 9am / 121230pm ish (stressing the ish!) and about 4pm then dropped the 4pm at about 8/9 months
when your little one is a year old all this will be such a distant memory!