Help!

I married Tayo even though we were not medically compatible (blood-wise). I am AS and she was also AS. I am not sure why I got married to her. Perhaps, it was because of her mesmerizing look, or because she was a very pleasant woman, or because we got on so well during our courtship. After I proposed to her, she suggested we went for blood test which confirmed were both sickle cell carriers. We were devastated, yet we went on with the marriage trusting God for a ‘miracle’.

A couple of years after our wedding, we started trying for our ‘Miracle baby’ but to no avail. One Sunday evening, after dinner, she complained of severe dizziness and nausea, I immediately knew it could be that she was pregnant. The next day, I drove her to our family hospital and the doctor confirmed she was 8 weeks pregnant. We were happy and at the same time frightened about the genotype of the baby. Few weeks after this, she woke up screaming and bleeding, I rushed her to the hospital and the doctor said she had mis-carried the pregnancy because there was a problem with the foetus. We were advised to wait for a while 
before trying for another baby. Six months after, she got pregnant again. I was happy and I prayed for her not to lose this one. I don’t know if I should say God answered my prayer partially because when she had the baby, it had to be through caesarean section, and she had to be transfused. The baby was born and we named her Oluwaseun.
Few weeks after Seun was born, she slept and she never woke up. The autopsy stated that it was cot death and that she suffered from sickle cell anaemia. 

Things got worse between Tayo and I. We got into fights every now and then. I guess we were mad at each other for getting married. A year on, Tayo got pregnant again and gave birth to 
another girl through caesarean section. Shocking and sadly enough, she passed away some few days later. I wasn’t sure if I should be angry with God for giving me these challenges or 
with Tayo for leaving me here on earth with Seyi (the baby). I tried my best as a father to care for Seyi, though it was a bit challenging taking care of a child and going to work. I couldn’t leave her with any member of the family because she’s the only thing that reminds me of my wife. I was giving her a bath two days ago when she said something I am still yet to digest.
''Daddy... I am Seun’’ She had said.
I have never told her about her late sister, how she got to know about Seun was and is still beyond my comprehension. Now I am scared to touch my own daughter, my sunshine, my 
everything. I am scared as hell and I don’t know what to do. Maybe I am going crazy, maybe I am just being superstitious. All I know is that I don't know how I got myself here.