You have every right to feel down. You will feel better when the date is settled. Do you have an advocate? A partner, family member or friend who can help you navigate the system? If not, what about your GP (family doctor) or a Cancer Society nurse? Basically I feel you need someone to explain why they haven't prioritised your surgery and what the risks, if any, of a delay are.

It could be that you will be rung back soon but just in case it might pay to get some support in place.

I'm a non-assertive person so find this sort of thing hard. My project manager son helped a bit last time. I also found that tears worked too or just blurting out exactly how I felt so that the person dealing with me was forced to take action. Sometimes being stoic just doesn't cut it.

1996, ovarian cancer surgery + cisplatin and taxol.
September, 2007, SCC of left lateral tongue. Excision.
October, 2009 recurrence in scar tissue, T1NOMO. Free flap surgery from left wrist - neck dissection. 63 year old New Zealander. No chemo, no RT.
February, 2014. New primary in left buccal mucosa. Marginal mandibulectomy, neck dissection, right arm free forearm flap. T1N0M0 but third occurrence and some areas of concern: RT started 8 April and finished 19 May.