I need some advice

m 38m and my wife is 37f. During intercourse I feel an orgasm coming pretty quick usually 10-30 seconds. So I pause and let that feeling go away and resume again until I get that feeling again. So on and so forth. After about the 4th time of stopping right before cumming all the good feeling from sex goes away. The sensation of going in and out stops feeling great and starts feeling no different from touching any other skin on my body. It's enough friction to keep my penis hard but just barely and it will often start going soft after this point and my wife has to put her mouth on it to get it back up again and then I can go for a little while but it doesn't feel like it does in the first minute and I can never cum after this point even with much more intense stimulation. She can give me the porn star blowjob after that and I still can't come. It's like all my sensation goes away.