Hi trying4baby88, I know there is a condition where you can be"allergic" to or have a sensitivity to your partners sperm.
I have a friend who had this problem with XH I'm not sure what the treatment was but I know she did use something to soothe the burning.
They had 3 children together so that wasn't a concern for them.
She did have to get a diagnosis from the doc though so probably best if you go to the doc and get it checked out.
I'm sure once you know what it is you'll feel better and can get onto fixing it up and TTCing without the burning and worry.

Good luck