I'm sorry to hear that your birth experience was so traumatic for you, but glad that your baby is ok. Were you offered a "debrief" appointment with a doctor or senior midwife? I work in midwifery and we know that going through the birth details with a professional can often help to answer some questions, as you tend to get swept up in events at the time. You or your birth partner may not have felt able to question decisions, or understood exactly what was happening, and having the chance to talk through this may help a little, and I've heard that most women find the appointment beneficial.
One of my midwife colleagues is a big fan of journalling. It can help to write your thoughts down, and to get them in some sense of order. This is a very good idea of you're thinking of making a complaint about your care (and if you think you have good reason to complain, I would strongly urge you to do so!) but even if not, research had shown that the very act of writing stuff down is therapeutic.
Try not to worry about missing these first few weeks, even if you'd had the most perfect delivery, you'd still be on your hands and knees, praying for some sleep. Those first few weeks pass by in a complete blur for everyone! You're often told that it's the "most wonderful time in your life", or that it's such a "special time". In reality, it's often a complete nightmare with painful breasts, CS wounds and/or perineums, not to mention back pain, swollen feet, bladder irritation, lingering PGP or carpel tunnel pain,.etc etc. Low moods are common, probably mostly due to the constant broken sleep, but also wild hormone swings, not to mention the sheer relentless workload of looking after a new baby.
Be kind to yourself and ask for help if you need it, especially if you're having nightmares, flashbacks, or physical issues that are still worrying you. Hassle your GP if you need physio referrals, especially if it's for bladder issues (I'm always banging this drum, bladder leaks are NOT NORMAL, and women shouldn't put up with them!!) And if this is your first baby, do try to join a mum and baby group, they're invaluable for just getting out of the house and talking to another adult. Babies are lovely, but they're a bit boring when you're stuck indoors with one all day.