Pelvic Pain, Heavy Periods And Nausea. Abdominal And Transvaginal Ultrasound Done. Findings?

Question : What could this ultrasound actually mean? I had a pelvic abdo u/s and a trans vag u/s 2 months ago due to pelvic pain, post coital bleeding, heavy periods, nausea and pressure. I saw gyn XXXXXXX registrar a month after, she said there was a cystic structure separate from the left ovary measuring 4.8cm x 2.9cm x 3.8cm. She said they do not know where it actually is at the moment. Saw consultant gynae specialist 1 week ago. The pain lower left abdo is on and off regardless of cycle and is becoming more severe, the doc put me on morphine tabs because of it. Anyway, she said it probably is either the fallopian tube or my peritoneum(?) wall, even possibly the ovary as although it is completely free from ovary on scans, it could be different internally? Anyhow she is booking me in for a laparoscopy to have a look whats actually going on and to get it out of me, as i told her i can't take the pain anymore, nor the nausea, tummy expanding, slightly more raised out lower left - it looks v odd. She said as there is a waiting list if the pain continues to come on really bad i should get down to emergency dept so she can do an emergency surgery. So basically they dont really know what is in there and where it is, the pains are on and off but severe when they do, although masked by morphine, it spreads to groin and left thigh/leg. Im nauseated a lot, pale as a sheet, skin itching, tired and wiped out, feel ill to be honest. What could be going on, should I be worried, and should I take her advice to have surgery quicker and go to emergency dept? Thankyou.