One thing I’d suggest is weighted kegels. They’ve been written about a lot here. This is my take: Ike - harder erections!!
But as your dick gets bigger through PE, you might have to accept the trade off of lower angle erections. A bigger dick has more mass, and the ligs that used to hold a smaller dick up at a high angle now have to hold up a bigger dick, sometimes at a commensurately lower angle. Still, try the weighted kegels. I’m bigger and older than when I started, but my erection can still get to about 10:30 when I’m well aroused.