Where can you get advice on an R & R?

You can post it but I don't see how that would help if you don't at least post a sample of your work on here as well. We won't be able to tell you what may or may not be working if we don't see the work. Posting the rejections you got won't help. People will only be able to guess what might be wrong. Posting your work in the Share Your Work section is best. People don't even need to see your rejections, they can tell by your work what might not be working, etc.

If you look at the "seeking beta reader" sections you should be able to find people who can offer some advice.

The problem is that deciphering R&R requests and manuscript fixing is such a skill that it will be hard to find a decent assessor for free or for a swap. Most professional manuscript assessments cost in the range of hundreds of dollars, and you need to vet the person who does it.

(I know a person offering MS assessments who I would consider barely literate, its quite a minefield).

I know a superb book doctor who does this sort of thing, but you're talking four figures easily.