Always make sure to support your lower back with your arms.
For starters, suck your own dick requires a lot of bending, among other things, and even though there are certain and blessed men who can suck their cock while standing up or sitting, the easiest and the go-to self-sucking position for most males who does self blow job is lying on their back.
It may seem uncomfortable and even painful at first, but everything is worth it.
Gosh, Abel, how hard is hard? I find myself keep coming back to look at this.
Your new party trick is not the cause of your sore throat.
Big, I see no reason for you to worry.