Can I sue my child's pediatrician?

Can/should I sue for this? 3 months ago my 2 y/o had a normal looking diaper rash. I put Desitin on it but 3 days later it still wasn't getting any better. I called his ped. and was told she was unable to come to the phone. The receptionist has a nurse call me back 2 hours later and told me try Balmex. I tried the Balmex for a week and it didn't help. I called the Ped again and wanted to bring my son in to have it looked at but they said they didn't have an open time to see him and they would have the doc call me back later. 3 hours later nurse calls and says doc said to try OTC Chlortrimizole. I tried it for 2 weeks and the rash got much much worse and was obviously painful to my little guy. I called the Ped again and was again told that they couldn't see him that day but would try to fit him in the next day and would call. They called the next day and said the doc would see him if I could get there in 10-15 mins before she had to leave. I told them it wasn't possible because I live 30 mins away but could she please wait and I will get there as fast as humanly possible. They said she couldn't wait. I took my son to the emergency room that night and they gave us a script for Nystatin for 3 weeks. 3 weeks later the rash had spread all the way up to his belly button and he was screaming in pain every time he peed or pooped. I called the Ped again and and again was told the doc cant see him that day but to buy some Lamisil cream and Vitamin A & D cream and try that for a few days. A few days later my son has boils and blisters on his butt, groin & legs. Called the Ped again and made it clear that I was very very upset and NEEDED to get my son in to see his doctor TODAY because something is serisously wrong. The receptionist again told me that they couldn't see him that day but would call me tomorrow if something opened up. I lost it and started shouting at this poor lady and demanded to speak to the dr. on the phone RIGHT NOW and she hung up on me. I picked my son up and we went to the emergency room. The Dr. took one look at him and said it was an advanced staph infection and wanted to know why I hadn't gotten him care sooner. I went through the whole story with him and said that if his Ped had gotten a culture of it 2 months ago they could have stopped it before it got bad. Now, my child has a staph infection that got into his organs and will be hospitalized and very sick for weeks. I feel like the worlds worst mom for not screaming in the dr's faces and demanding they DO SOMETHING sooner. I just want to know if I have any grounds to sue this Pediatrician for the costs of my son's now expensive medical care and pain and suffering.