Can't make love with a glove...?

You get used to it. Personally I never noticed any difference, could ejaculate just as easily but some guys do have the problem you are experiencing. First make sure you have the right size-- if the condom is really constricting that can throw you off your game by being uncomfortable-- so if that is the case, try a larger size. I certainly was uncomfortable with tight ones and switched to Magnums and they worked great. Of course if they slide off when erect they are too big.

Also you can tense your scrotum with your groin muscles as you have sex-when ready to fire-- and do that repeatedly while having intercourse and that can jump start the climax and get you to ejaculate when you are ready.

Assuming, since you say you can’t finish any more, that the problem is you not ejaculating (as opposed to you having a hard time maintaining an erection with a condom on), there are a couple of things you can try. First, experiment with new positions, especially if you typically use the same one most of the time. Trying a different position can cause different parts of the penis to get stimulated, which may do the trick for you. It’s also possible your penis may have become a little de-sensitized; using a penis nutrient cream (health professionals recommend Man1 Man Oil) that contains acetyl L carnitine may help; this ingredient is neuroprotective and can help maintain penis sensitivity. Good luck!