A brief intro and a question

I just got my Helix Syn in the mail today and will be it trying shortly. I've dabbled a bit in anal play but not much. This is my first prostate specific device.

The reason I'm here... I have no problem getting hard and can stay hard during sex for a long time, to the point of giving up before I cum. Not being able to finish happens maybe 1/4 to 1/3 of the time. Not a significant number but certainly enough to be very frustrating at times. I'm early(ish) 40's FWIW. I've done some research on the subject which results in a few articles worth reading and the rest are trying to sell something, also most articles are focused on PE and not working towards lasting less time. I've read some on the PC muscle - some articles say a strong PC can help with premature ejaculation (opposite of what I'm looking for) and that a relaxed PC will make you cum faster. This was just recently I read this. When I'm trying to cum I flex my PC sometimes for an hour straight which eventually results in half my body being tensed up. All this apparently is working against me. There's certainly a mental content as well, I usually get stressed about not being able to finish before foreplay even starts.

Anyway, I hear having better control of these muscle groups is definitely beneficial and not just flexing them solid for an hour at a time. And it seems muscle control is needed for success with this device so it seems it might be a good training tool - which is why I got one. I've also read prostate massage is helpful as well for an extra bonus. So here goes....

Does/did anyone else have the same issues? and did this product help of hinder your success?

Thanks,
Take care