Hello and welcome to the frog forum !!
Mice should only be fed to pacman frogs once a month at the most. The best staple for them are nightcrawlers with dubia roaches and crickets as a variation. Mice are high in fat. This will lead to a fat buildup in the body and eventually the fat will begin accumulating in the eyes because it has nowhere to go.
Pet stores are notorious for giving some of the worst advice for pets. Nine out of ten times their advice will get your frog killed.
To make sure your frog gets all the vital nutrients it needs, you should dust its food with calcium powder every other feeding and multivitamin powder once a week.
The sores may be fat buildup. Or maybe an infection. Pictures would definitely help if you can get any.
I think your frog may be extremely impacted. Mouse bones can sometimes do this especially if the proper nutrients are not offered.
I would get in contact with a vet experienced with amphibians ASAP
I will post some questions about the husbandry soon
Edit: here are those questions


1----what 'kind' of frog is it ( what species)
2----please include a photo of the frog
3----Please include a photo of the frog's current enclosure
4----size of enclosure ( W" x D" x H" )
5----# on inhabitants - ( if there is another frog --- is there a size difference ? )
6----has or was the frog kept with a different species or with any other tank mate
7----is there a new tank mate----was the new tank mate quarantined
8----what is the typical humidity level
9----what temperature is maintained
10---what is, specifically, being used to maintain the temperature of the enclosure
11---describe the enclosure lighting ( very specifically)
12---describe enclosure maintenance ( water changes, cleaning etc)
13---what kind of water is used
-----for misting
-----for the frog's soaking dish
-----is de-chlorinator used / what brand
14---material(s) used for substrate - be very specific
15---enclosure set up:
-----if recent - describe how the enclosure was cleaned
-----plants( live or artificial) if artificial plants are used are they plastic or fabric
-----describe wood, bark , and background materials
16---when is the last time the frog ate
17---have you found poop lately
18---how often is the frog fed
19---what size feeder is given
20---what other feeders are used as treats
21---what is the frog's main food source
22---do feeders roam free in the enclosure or is the frog bowl fed
23---vitamins - what brand and how often
24---calcium - what brand and how often
25---was the frog without calcium for any period of time
26---approximate age of the frog
27---how long have you owned the frog
28---who cared for the frog before you
29---is the frog wild caught or captive bred
30---how often the frog is handled -- are gloves used ( what kind of gloves)
31---is the enclosure kept in a high or low traffic area
30---has or was the frog properly quarantined (yes or no)
-----for how long
32---has the frog been treated with any medication:
-----for what
-----name of medication
-----for how long
-----what dose
-----was medication prescribed by a herp vet