Help me save this iguana

First of first, at the moment neither I or my friend can take her to a vet, because in our country it is hella difficult. A friend bring me this iguana, he bought it a few days ago with another one, but he put them both in a single cage, I don't know the size tho, but the thing is that I think it may be cause of that , and that he gave them only lettuce to eat and that is not too nutritional.

The thing is when I saw her, she didn't have any strength, like don't even move at all or grab anything, that in my experience with iguanas they all do, she was dark, got a lot of stains, a lot of fingers have no nails, its TOO skinny, i dont know if it too clear in the photos but its too skinny even grabbing her its obvious, got this thing in the body that i thought it was dirt but i dont know now, you can see how its his lip, he told she doesn't eat, I try feeding him but never, I opened her mouth and put the food in there but she just let it be, like don't even bite it or throw it, nothing, I gave her a bath, get her some sun , approach her, and i will blend some food to give her, i see that shes i bit better, she grab a little bit my arm, not with a lot strenght tho, move her leg when i grab her, walked a little bit and i tried feeding her again and she opened her mouth a little bit but throw it.

What yall think i should and shouldnt do?

PD: sorry if my grammar is bad, english is not my first language, im from DR.