I think a big part of dealing with endo is acceptance. And by that I don't mean not having the occasional day when we're screaming "THIS IS NOT FAIR!" or "WHY ME??!" because we wouldn't be human if we didn't do that!!
I was diagnosed in 1992 and since then I've seen loads of things change in terms of how the disease is treated, and for the better, but the one thing that has remained constant is the unpredictability of the disease itself. I had my left ovary taken out about 8 years ago because it was constantly developing big cysts and in the end, after all the ops to remove all of the cysts, the ovary was ravaged and probably not doing its job anyway, so out it came. Since then, my right ovary has been completely quiet and well behaved in terms of cysts (I have scans every six months to keep an eye on it because of how the other one behaved) but I have been on and off Zoladex/Prostap for the general pain during that time. Last year, three months after I had finished a 6 month course of Zoladex, I went for one of my routine scans expecting it to be just that, routine, and completely out of the blue a 5 cm cyst had developed on my remaining ovary. I was absolutely gutted and so was my gynae, because the state of my insides after years of poking and prodding means that any surgery now is going to be a big deal involving bowel and bladder surgeons, but I went straight back on to the Zoladex for six months and it zapped the cyst away completely, there was absolutely no sign of it, which was again something we hadn't expected.
I think nowadays because everything is so 'instant' people think that there must always be a quick fix for everything, but endo won't play that game. And that's what I mean about acceptance being a big part of it all; there's no point getting cross at consultants or doctors for not being able to do anything to fix us because endometriosis is still very much a mystery to them, for the most part. As Nosh has said below, everything can be going really well and then boom, something happens and you're off on the roller coaster again. Or conversely, like me and that cyst, everything can look really black and then something totally unexpected happens to make things better. There's just no second guessing it, and that's really frustrating, but that's just how endo is. It's a pain in the backside (quite literally, sometimes!) but once you've got your head around the fact that is IS so unpredictable, it makes everything so much easier to deal with.
Have you seen the book Endometriosis For Dummmies? I love those Dummies books anyway, but the endo one is brilliant, it gives you all of the information you need about endo without scaring the hell out of you like some of the more weighty books do. Even after all this time, if I'm feeling a bit out of sorts I'll go and flick it open and have a read to remind myself that I'm not going mad, I just have a disease that's playing silly buggers with me. Have a look on Amazon.
Good luck with the injections, I'd be really interested to hear how it works out for you, particularly as you're having the 3 month ones. Feel free to message me if you want to
Take care, and lots of love