I agree with others that your GP sounds dreadful - it's no wonder you're worried with that type of mistreatment by medical professionals. While no cure, there are treatments that help. I'd suggest looking through the NICE guidelines on endo. Even if it's not the cause - there are multiple menstrual disorders - it's a good starting point for seeing what should be happening to look into it for you.
That said, there is no guarantee of control whichever route one does, much like with the rest of life. It'd be nice, but it's important to recognize, as scary as it is, the limits to what we can influence. The best I can recommend is having someone supportive who will push for supportive staff if you end up with assholes.
Others have already mentioned where C-sections haven't gone smoothly. Surgeries can be great, but they can also get complicated and people can be assholes even when things are scary. I've had lovely HCP and ones who seemed to think it was a moral failing on my part to be mocked.
I had one home birth that went picture perfect with the HCPs, another I was repeatedly left on my own, belittled, ended up with me in the OR because of the previously mentioned medical fuckup largely because the homebirth midwife did not support my choices & wanted control over me. She literally refused to hand my child to me until I agreed to the 3rd stage injection (which caused pain far, far worse than the labour I had just been in. I chose with the labour after that to have the injection after the placenta came out and it was so much better).
I had a hospital birth where I was left alone and belittled and pushed into things I didn't want, another where I had the nicest people and had someone with me throughout and even when they clearly disagreed with my choices (they did not like me wanting to postpone the afterbirth injection), I felt supported in making them.
I was left on my own repeatedly while on the high dependency ward shortly after coming out of general, which became a major issue when I couldn't pick up my crying newborn.
Really, the people make or break it even when things go pear shape and the matter of birth or even the location doesn't change that much. My 'good' hospital birth involved me freaking out really worse than I'd ever had during a birth before (hospital settings tend to set off my CPTSD badly) I was absolutely convinced everything was going wrong, having the emergency button hit more times than my attending midwife had seen (so I wasn't entirely wrong there, but it wasn't to extent my scared mind thought it was), having to be rotated by multiple people while pushing to help my son's shoulder get unstuck (still ended up with no tears, I've never torn in all my four births, just mild grazes with my first and the swelling each time), and needing a really hands on third stage as my placenta ended up being far larger than it probably should have been (the midwife commented on it as it took up their whole top of their little wheely table of supplies) and took longer than is normal & I'm a bleeder. I still think it was a good birth because I felt supported throughout and afterwards even with what 'went wrong' whereas my homebirth that had no complications until the midwife yanked the cord was terrifying because I felt like I was up against people while giving birth as I wasn't sure how to deal with the fact I'd got assholes attending. Figuring out a plan for that I think is better than thinking we can control how birth is going to happen.