Welcome to the forum and congratulations on the baby! I'm sorry her birth was so difficult. It must have been a very overwhelming experience.
Your friend was absolutely wrong about breastfeeding. It happens to be increasingly popular, and for many moms is a really vital aspect of their bonds with their babies. But what matters here is how YOU feel about nursing- if it's something you want to try, and something that you think could help you bond with your child, then that is all that matters.
If you want to nurse again, I suggest simply offering the breast to the baby as often as she is willing to take it. After 3 months of bottles, there's a good chance that she won't really know what to do with it. If that is the case, the suggestions in this link http://kellymom.com/bf/concerns/child/back-to-breast/ may help encourage her to give it a try. The skin-to-skin and instant reward techniques are said to be especially helpful for reluctant nursers.
Since you have done bottles for 3 months, you're going to need to work to rebuild your supply. That means either getting baby to nurse a lot, and/or pumping as much as possible, using a high-quality double electric pump with correctly sized shields. A hospital-grade rental would be ideal. You're going to want to pump as much as possible. 8-12 times per day, for 20 minutes at a time, would be ideal. But that's not possible for all women, so don't feel like you're failing just because you can't achieve perfection. Every little bit you do will help build supply. Milk supply = demand, so the more you pump and nurse, the more you'll make.
Now, in the US there is no way we'd recommend introducing solids to a 4 month old baby. I believe the recommendation in the UK is the same- that babies should be exclusively on the breast or on formula for the first 6 months.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"