It's OK to stop and take care of myself.
I doubt if anyone is telling you this. No one is telling me this these days. But it does take me back to my first marathon in 2005. I listened to all the coaching I received, but some of it seemed counterintuitive. For example I remember the coaches saying if your shoe strings got loose and felt uncomfortable, stop and take care of it. If you needed to use the restroom, stop and take care of it. If you felt a cramp, stop and stretch it out.
None of this made sense. It will take longer to finish. You might stop and not be able to start again. You will look foolish or like an amateur who doesn't deserve to be there. Any of those scenarios is possible, but probably the person who listened finished with a better time, feeling better, and knowing that they belonged there.
Please stop and take care of yourself, even if it seems counterintuitive!