please help — bad infection—

Hi everyone- I must just say that I feel terrible & I wish I caught this sooner- Anyways one of my girls has developed a big infected looking wound on her upper leg – you can see a wound and its all red and hard around that whole area- she seems to be feeling okay just basking more -I dont handle my guys daily and just noticed this tonight but it looks painful- I have no turtle vets around me so I got some chlorehexidene and silvedene creame and I am hoping with salt bathes and drydocking her this will be enough– does anyone out there with experience have any advise??- I feel like absolutly terrible and I’m worried that because it seems soo infected that she may become very sick!- Please Please if anyone can help I would be very greatful thanks –Heather–