Jemstar, I felt very like you after I had my first baby. I was really lucky to meet a great bunch of women here on S&B that really helped me. One thing that I did discover is the need to be strategic about your shopping. Plan, plan, plan if you can. So I try and do something like this:
List occasions that you need clothes for. Literally everything you do in life. So something like:
Park with DC's
School run
Coffee with friends
Dinner with DH
Lunch with family
Think about what you want to look like when they happen, what do you want to be wearing? Get magazines, use Pintrest, watch other women etc.
Make some notes of what you would like to wear and look at what things seem to crop up the most. So skinny jeans, blazer, etc might feature in a lot of outfits and therefore these are the things you should try and spend a bit more on, as these things will work harder than others.
Rather than use a shop for a style, I tend to use a certain shop for a certain item if I can. So, 90% of the time I know I can find, blazers in Zara, jeans in River Island for the high street, JBrand for premium, casual tops in Whistles etc.
Hope this helps, although I do not purport to be an expert at all! I just recognise the feelings and thoughts you mention above.