Right, first things first, deep breath! You are doing a fantastic job and by the sounds of it doing everything i did! I read and read and read everything so when my first popped out and didnt sleep when he should, and didnt get on with breastfeeding I was devastated and thought I was doing something wrong. After a couple of months, my hubby made me see sense and I realised that babies don't read books so behave as babies and each little bundle of joy is a little bit different. I had my second in January and we had such a horrible time of it, with him being born by EMCS 4 weeks early and spending 4 weeks in SCBU. That said I'm so much more relaxed this time as I've learnt to go with his cues for feeds and naps.
Of course I still have days when I'm tired and cranky and everything seems too much but they are just bad days and tomorrow's a new day. Try not to worry about what the books or other people say you should be doing, go by your own instincts, I didn't trust mine but actually once I started trusting myself things got much easier. No one knows your baby as well as you do.
My baby is now 7 months and some days will have lots of naps and other days hardly any. I also find that when were out and about he sleeps lots as in the car and buggy most of the time. But when were at home he'll just 'catnap' have odd ten minutes here and there, half the time I dont bother putting him in his cot.
The only times I really have routines are mealtimes and bed. We usually eat around the same times and bedtime is always the same, starting at 7 with my youngest, finsihing by 8 with my eldest. Other than the odd couple of tv programmes my eldest likes, and a bit of a quiet time after lunch we dont stick to a strict routine. Maybe stop following a strict routine for a couple of days and see what your baby does, you might find she slips into a natural routine anyway.
Finally babies change all the time, due to growth spurts, teething, change in eating habits and just getting older and managing with less sleep. So by the time you go back to work, she'll probably have changed all over again. But try and stay positive, I'm sure you're doing a fab job, you just need to believe in yourself, and oncve you relax, you'll probably find baby relaxes too!