I would definitely get that checked out asap. I am super plus sized as well and with the size of my belly girth and tummy roll I shockingly didn't have any issues (praise God)...I was just told to shower at least once a day, allow the soap suds to wash down over my incision site or to use a soapy squeeze bottle while showering, no rubbing/scrubbing, just let the water run down over the site to rinse and pat dry...but...definitely keep it dry and add nothing.
Feel better soon, congrats on baby and best wishes.
Is important to keep it dry and not let your skin hang on the incision. I bought the expensive paper towles that are cloth like and tucked it between my lower gut and where the incision was. I kept it from allowing skin to skin contact and changed it every few hours. When I changed it would wet it a little to take it off in case it stuck to the incision. Not sure if that makes sense but I didn't have a problem healing or keeping it clean and uninfected.
I would say get checked as well... My cousin had her babies a month ago and she a big girl as well.. but her stitches popped an she was in pain as well.. It also started to get infected.. to be on the safe side go get checked.. an no she didn't feel it pop or break..
In ventral what you can apply is dry gauze to the area and change it a few times a day. It helps absorb moisture and keeps bacteria from growing. Also cleansing the area with normal saline before applying the gauze will help keep it clean.
I had a c section and was told not to put anything on it because the skin has to stay dry. Call your doc for clarification.
I would suggest getting it checked out. It could be infected and that might be why it's so painful.