How young were you when you started getting chronic pain? Did you ever feel like a faker?

I'm 25 now, but I've had unexplained chronic pain since I was 8. I've had years of countless tests with no answer, except for fibromyalgia which I don't want to accept without further testing and specialists. I'm waiting to see rheumatology in a few months. I'm suspecting EDS. I'm on daily and as required pain killers, but I can't medicate at work or if I'm going to be doing any driving that day (it can be dangerous so I won't take the risk) so I just have to suffer through.

Usually I look as if I'm not in pain at all, though I'm almost always in pain. It's only obvious when it's a flare up and it hits a 7+/10. My back, neck and shoulder muscles spasm and I get sciatica like pain in one or both hips, so when I'm hurting I'm usually quite stiff and/or limping. I feel like it looks fake, but I'm genuinely hurting a lot and also trying to protect my body from moving too much to reduce some of the pain.

I feel like because of my age, the fact my pain is usually hidden, often starts out of no where, and that I literally have 0 answers or explanations for it, that I seem like a faker when I talk about it or when a flare happens and I can't hide it. I'm battling that hard in my brain EVERY time I get a flare up around strangers, colleagues, or friends.

Does anyone have any advice?