I think your question contains many personal parts which I can't answer and should be addressed by your gynaecologist. However, I will try to bring some clarifications to some of your raised issues:
If you have PCOS are you more likely to have endometriosis?
Actually, two studies have investigated this.
The first study was conducted in 1989 and included 91 women. Here the results:
Pelvic endometriosis was observed in 15 of 91 women (16.5%) with
laparoscopically confirmed polycystic ovary syndrome. There were no
significant clinical differences among those with and those without
endometriosis. The groups were of similar age, parity, and ponderal
indices and had similar incidences of oligomenorrhea, hirsutism, and
infertility; the serum concentrations of LH, FSH, LH/FSH, prolactin,
testosterone, and dehydroepiandrosterone sulfate were also similar in
each group. However, women with polycystic ovaries and endometriosis
presented more frequently with regular menses (40 versus 14.5%; P =
.05) and less frequently with secondary amenorrhea (0 versus 38.2%; P
= .05) and galactorrhea (0 versus 9.2%; P = .05) than the women with polycystic ovaries alone.
The authors concluded:
Endometriosis appears to be a coincidental finding in polycystic ovary
syndrome, and its development does not modify significantly the
clinical picture or biochemical profiles of these patients. However,
menstrual patterns seem to be affected.
Similarly, a second study, conducted in 2014, reported *a significant association between endometriosis and women with PCOS with pelvic pain and/or infertility.
So to conclude: while a causal link has still to be determined, presence of endometriosis and PCOS is not uncommon. The latter study showed an odds ratio of 19.7 (95% CI, 9.6-40.2) of finding endometriosis in PCOS (p<0.0001)
Now the diagnosis of PCOS relies on the Rotterdam criteria ie two out of three of the following are required to make the diagnosis: oligomenorrhea, hyperandrogenism, and polycystic ovaries on ultrasound.
While the diagnosis of endometriosis relies on histologic evaluation of a lesion biopsied during surgery (typically laparoscopy).
As a side note, according to uptodate:
Definitive diagnosis of endometriosis is often delayed because the
symptoms of endometriosis are vague, the symptoms overlap with a
number of gynecological and gastrointestinal processes, and a surgical
diagnosis entails risk. Studies have reported an average diagnostic
delay of 7 to 12 years in women with endometriosis.
You may wish to consider reading following websites on endometriosis and PCOS:
Barbieri et al. Diagnosis of polycystic ovary syndrome in adults. Uptodate. Aug 2016
Schenken et al. Endometriosis: Pathogenesis, clinical features, and diagnosis. Uptodate. Aug 2016