I have the same problem when rolling one on. But a friend showed me how to sort of solve this problem. I’ve always enjoyed wearing a condom to wank / be wanked but only being just about four inches it slips off very easily often before I can fill the teat. So he showed me how to get it over my balls, well did it for me. It’s fairly simple but only if you have a ring or strap around your balls. An added beniifit is the condom tugs at your balls increasing your pleasure.
I feel ya man. It's really embarrassing too if you have to ask a buddy or another guy for one and they hand you a magnum or a wide fit and you have to explain why it wont work for you and if they have other ones