Chicken help needed very badly! Called 10 vets already and no one is available today

I could really use the chicken community’s help right now!

My poor 6 year old Wyandotte, Scully, has an impacted egg we hadn’t noticed until this morning when my husband was feeding the flock and she wouldn’t come out to eat. We eventually got her out and she was drinking water but after examining her rear out of fear that she might have vent gleet, we saw it was definitely an impacted egg.

I tagged this NSFW because she also has a second hole near her cloaca that has…… maggots. We have no idea what to do. She was acting fine and we had no suspicions she was having issues until this morning. After calling 10 different vets nearby that all have either said they don’t take chickens or their chicken vet is out today, I am coming to this community really hoping someone might be able to help.

Is she too far gone? Is this beyond help? I know the typical solution for impacted eggs but the extra wound is freaking me out that she might be not save-able at this point. Any advice or kind words would be really appreciated right now. Thank you for your time.

EDIT: thank you everyone that offered advice!! This is a truly heartbreaking and stressful situation and just having people who care and understand means everything. After more inspection it looks like just fly strike, my husband was confused because of the blood. I have ordered Vetericyn on the fastest shipping possible and it should be here in a few hours and I also went and bought Epsom salts to soak her to hopefully drown some of the maggots. (Also obtained some other supplies mentioned in the articles some of you guys provided) I really can’t tell you all how much your advice has soothed me and helped my sweet girl. Thank you again and hope for her recovery!!!