Thanks Carley for your answer. It has helped a lot. My pain has now gone again after diet changes ( doing the endo diet ) and my period. So yeah it has come and gone like this all year and is frustrating. I’m going to try to wait to see the specialists but get on them to get in possibly earlier as you suggest. I want to talk about hormones with them rather than another doctor as I’m just so tired at this point of talking to people that don’t know anything about it and then getting sent to more people who don’t know about it. The PT is an interesting idea as I’ve never tried that for endo. Thanks so much!!

A lot of what you're describing is similar to my initial experience, but I'm not in Canada so I can't make any recs for docs, etc. Go see the specialist for your appointment, but also call them back now and ask if they can get you in (or on a waiting list) for additional services like physical therapy now based upon your left side pain. In the meantime, if you have access to mental health services or a support network, shore them up and lean into them! This can be the biggest source of support and coaching on how to make yourself heard. Also keep a detailed and dated journal of your symptoms.
Excision surgery helped but it wasn't a cure-all. I have not yet had a hysterectomy, I'm stage IV but most of my endometriomas were attached to my digestive system. They did remove cysts and ablated my adenomyosis but the success of the ablation has been limited.
Nothing has helped with managing the pain the way physical therapy with a pelvic floor specialist has.
Talk to the specialist about your concerns about hormones and why. My family has a history of stroke and estrogen happens to be a big part of the problem. But after some tests and discussing it with my doc, progesterone/aygestin has become a treatment godsend whereas letrozole can dangerously raise my blood pressure. I bring this up because I thought hormones would not be possible for me but now they're another tool in the toolbox.
But you have to explain the whole family health history and spell out all your concerns to them. Be loud, repeat yourself. Ask to see another doctor if you're feeling dismissed. With endo it's not a quick fix or one size fits all, it takes time. Good luck!