Not having a strong plateau phase

My job has been mentally draining lately, so I thought I’d masturbate. However, when I’d get to the plateau phase it wasn’t as strong as it usually is and I’d orgasm almost instantly. I orgasmed during three separate times, but the same thing happened. I used a vibrator in all orgasms. This is probably normal, but I’m just curious lol. I’m not sure if it’s the stress affecting me, but does anyone else have the same problem when they’re stressed?