Battling through depression?

Hi. I’m a mother of a special need child. Everything was great until labour, things happened and my girl suffered severe brain injury. We lost her for 10 mins, she was successfully resuscitated but because there was no oxygen to her brain for very long, she suffered. It was a very tough journey but we braved through the storm. It’s even tough because I lost my beloved dad to Cancer before I got to know I was actually pregnant. He was my superhero and he was always there whenever I had problems. It has been 10 months. My babygirl spent most of her life in the hospital. She was in NICU for more than a month before she was discharged and we had to admit her back again for aspiration pneumonia and then she was hospitalised for more than 6 months until we finally brought her home. During this period, my husband only managed to take a week of break from work otherwise we are not able to sustain financially as I had to take a longer unpaid leave. We were both exhausted. We are under palliative care and it was reassuring as they are always there to help us out whenever we encounter problems (low oxygen etc). Our little girl requires us to look after her 24/7 as she is on ventilator and we had to ensure the mask is on her correctly and oxygen levels/heart rate had to be monitored closely. She often has very bad dystonia that also makes her hard to sleep. My mum is staying with us, she’s not good with the machines but she has done a lot by helping us prepare food, house chores and also carrying our little girl, making sure everything is okay. We barely had time for ourselves. Whenever I had time in my hand, it’s either I had to rest or pack my orders as I am also doing online business to sustain financially. It has been exhausting. At times I want to break down but being the main caregiver, I know I couldn’t afford to. I forced myself to get on day by day, each day battling with my own little devil inside my head, making me feel anxiety. My mistake was that I did not open up to people. I kept it all in there. I soon snapped. I had really bad anxiety attack, I hyperventilated. My chest hurts, my whole limbs froze. No one could actually understand what I was going through. Everything that came out from people’s mouth felt like a dagger. I know they meant well but I felt attacked. I felt alone. Is this how depression feels? I’ve been trying my very best to brave through everything. I’m so afraid. I’m afraid that if anything happens to me, who will be the one taking care of my baby girl? She needs me.