I’m sorry if this is long but my 4 year old autistic son almost drowned in a lake and I have trauma.

I just need some helpful advice to let go of this horrible feeling

First of all I do not need anybody telling me I am a bad parent. I have heard so many cases of autism children drowning and I did not know drowning was the number 1 cause of death with children that have autism. So what happened was it was a typical family day and me my husband and my daughter with my son just wanted to take my kids to the park. He is level 3 is nonverbal. I live in a HOA area homeowners association and right next to the park there’s a small hill and in front of that is a lake with ducks. We have been to that park multiple times with no issues but I have noticed every time my son goes there he wants to go to the lake I have to chase him down every time to bring him back to the play area. Well last week was a nightmare. I always watch my son like a hawk my husband was playing with my daughter and my son was just playing on the slide where the play structure was I am never on my phone my daughter was saying mommy mommy look at me I check my son he’s still playing I look at my daughter on the other side for only 5 seconds I look back at the play structure next thing you know my son was gone. My heart was racing so fast and since my husband was with my daughter I was yelling where’s Noah where’s Noah I looked around the grass, swings, he wasn’t there and first thing my husband checked and thought of was the water. He was screaming he almost drowned. My husband’s clothes were fully wet he jumped in to go save him. Thank god my husband said he was not submerged in water his face was completely on the water and half of his head was out and his arms were flapping my poor baby boy was fighting for his life when my husband got him out the water he patted his back so hard and he coughed up all of the water. No cpr was performed he was not blue but when he did get out of the water it looked like my son fainted a bit so my husband had to shake and wake him up and that’s when he woke up and just started screaming and crying. After that we took him to ER right away his heart rate was at 200 and he had a fever of 103 the doctor 1 emt and the nurses rushed to take him in right away he was on oxygen and they had to give him fluids. Since he coughed up all the water X-rays were done they kept giving him fluids my baby boy was feeling so much better and the doctor said he was okay and he looks good. He was eating and drinking as normal smiling and playing. I thought I was going to lose him I threw up and was having a panic attack I felt like I couldn’t breathe. I have dealt with 5 deaths and losing my child would be a fuckin nightmare to me I probably would not want to live. I have terrible trauma from this makes me sick to my stomach. The doctor said he wasn’t in there that long and me and my husband caught it on time before it was fatal. I have asked about dry drowning but the doctor said that’s highly unlikely. I just can’t wrap my head around this but if I were to tell people they would say we are shitty Parents because we can’t watch our kids properly. Sometimes I hate myself for this and wish I would have done things differently. How can I feel better? Even though my son is fine now and is back to his usual self I still can’t wrap my head around this I can’t imagine the trauma he went through and as a mother this shit breaks my heart so bad. :(