Cock ring???

Tonight I asked my boyfriend if we could try a cock ring because I can not hit the big o!! I always feel like it’s about to happen but it never does. I have maybe 5/6 times in my life but it’s so frustrating because it’s always right there but for some reason never finishes! But I feel terrible for even asking because he told me he feels like he’s “not good enough” now. I just really want to try it to see if this will work but I feel like I shouldn’t bring it up again!