Feeling guilty for not feeling happy

My husband and I tried for 8 long years to have a baby. 8 years dreaming and wishing to be pregnant and to become a mother. In those years I fantasized about being pregnant and how wonderful it would be to carry our baby in my womb. After two miscarriages my vision of pregnancy was slightly tainted but It made me want it even more. Last year I finally had a successful pregnancy and gave birth to my beautiful rainbow baby. I love my son with all my being. The pregnancy was stressful and difficult . I developed a life threatening complication called preeclampsia ... And was constantly in labor and delivery, I gained a great deal of weight and was swollen beyond recognition that I didn't even take maternity pictures like I always dreamed. My naive image of pregnancy was shattered. I was in constant pain and worry over our lives. luckily I made it to 37 weeks and had my son via c section and once he was here I was over the moon in love and in awe of him. He was all I ever wanted and because of my infertility history and high risk pregnancy I was happy if he ended up being my only child. pregnancy had really traumatized me that I was really looking froward to putting it all behind me and get my self in good health, weight wise and just enjoy my son growing and then maybe think about giving him a sibling, but that was so far in the back of my mind because I really wanted to focus on myself and recover, To be the best mom I could be for my son. My son just turned 9 months and I find myself 12 weeks pregnant ( we were using condoms ) I was in a panic when I found out. I don't feel ready physically or emotionally. I wanted to put my experience far behind me and I feel like I'm right back there again. I'm extremely sick and this time experiencing severe migraines making to hard to be the mom my son deserves. I'm scared of developing the same complications I'm scared of something bad happening to be because my son needs me. At first I even wished I'd miscarry 😪 and I feel terrible for it after all those years of trying. I just don't feel happy, even after my first ultrasound. Will it get better ? I keep praying that my feelings change and I start feeling something. I'm just so sad for feeling like this. Someone pls give me advise or something. I don't mean to offend anyone going threw infertility. I'm honestly ashamed of how I feel.