I can’t get the big O so easily anymore

So I am not a young, just starting to explore myself, masterbater. I am almost 30 and have been doing this ever since I can remember. I have never had any issues masterbating clitorally or vaginally, I even have done some camming in the past as well so definitely not shy.

Recently, my boyfriend wanted to watch and I allowed him to, however, after 7 or 8 attempts over the span of 4 hours, I still could not climax. Ever since then, I have tried several different ways, several different times and scenarios, and eventually I do climax but what would normally take me 2 minutes or less is now taking me 20-30+ mins, sometimes with breaks cause I start cramping or I get super close and then completely lose it. And this is IF I’m able to. Sometimes I’m not even able to climax but when I have sex, it’s no problem at all. I usually cum vaginally within 30 seconds of penetration. (This has always been that way) so the only thing that h as recently changed has been him asking to watch the one time.

What do you think the issue could be? At first I assumed just “stage fright” but even alone it takes forever. 😩