I have this rash im concerned about near my groin and im pretty sure its jock itch but the only reason i have doubts is because ive had someone else look at it and compare it to stretch marks. but i dont remember stretch marks burning and itch so bad?

Fungal infection?: It may be a fungal infection but the only way for us to know for sure is with evaluation.

Need to examine: It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. You may try an over the counter remedy for jock itch. Ask a pharmacist at your pharmacy for a suggestion. If that does not resolve the matter in a week, it would be prudent to see your doctor. Wish you good health!