Clearly you need to stretch your foreskin opening. We have "done to death" the instructions to do this, and you should have no trouble figuring it out by reading back here.
Yes, if you were circumcised, you would undoubtedly have no problems with "excess" sensitivity or tightness, and retraction would never be a concern. Now of course I trust you understand
why circumcised men do not suffer from "excess" sensitivity and the process by which this comes to be so manifestly reduced?
That said, I venture to observe that were you circumcised, you might
still find it both "dull" and uncomfortable using a condom! There are just certain mechanics of a condom that are never quite "right" (but I hardly need to elaborate - again - how important they are

).
So I leave you with two things - no - three.
- Do the stretching.
- Any time "excess" sensitivity seems to be a problem, please consider why this is not a problem when your foreskin is covering the glans (and please note the spelling and meaning of that word). It is because your foreskin is very effective at both retaining and emulating lubrication - although your description of soreness from masturbation suggests this may actually be deficient (and that's another story).
I suggest you locate some "personal" lubricant - if you were already using this I would have expected you to mention it already - and use a little of this under your foreskin when you masturbate, and inside the condom if you are going to retract your foreskin.
- You know, I am really concerned that you have tried to "have sex" and found it "difficult to stay aroused because of" a lack of sensation. This suggests to me that you are far too preoccupied with your own sensations and oblivious to the real situation. I would suspect that your partner was none too pleased either - and not because you "lost your arousal". In which case (or in most cases anyway), you will need plenty of the personal lubricant on the outside of the condom as well.