Advice For A Fresh Start

Hello, I started PE two years ago and kept at it for more than six months, with religious consistency, with little to no results besides improved erections.
I followed the newbie routine to the letter (5 min stretches and 10 min jelqing, increasing gradually every week).
I plan to restart soon, would you advise to start with longer sets, since my penis already proved resistant to the newbie routine as it is?

One mistake I made in my previous attempt was probably not using heat with the necessary care. I simply did PE in a mildly hot shower, putting the penis under the water for five minutes before the session.
I’m planning to go with an infrared lamp now, but I don’t quite understand how much time should I expose my penis to it. Should I keep the lamp on for the whole session? Or just for 10 minutes as a warm up?
In other words, do these lamps have a threshold as far as maximum heating temperature, after which they will just mantain the temperature reached, or will it keep heating my penis until it is roasted?
Thank you for your help!