Mild ED caused by PE

I've been stretching for around an hour per day with about 6-7lb 2 days on 1 day off and I noticed that when I come to have sex my penis is simply not responding as it used to. I barely get hard and I need extra time to get aroused. Even then my erections are not that strong. I'm not really sure what I'm doing wrong.

If I take cialis or viagra I have no issues but I don't want to take it every time before sex.

When I take two days break it seems like everything is back to normal and my erections are strong as they used to be.

Any advice would be greatly appreciated!