Montgommery Gland Discharge and lump

Hi

I am 39 old female with 4 children. Last pregnancy was 2014. History - I had an introductal pappiloma in my left breast diagnosed in 2011. Also reactive lymphnodes at the time on both sides.

Anyone with a similar experience? My rigth breast have had enlarged Montgommory turbicles since my first pregnancy 18 years ago. I have always been told nothing to worry about. At any given time I gently squeeze them (rarely but now and again to check) liquid always come out. However for at least 3 or 4 years (haven't taken much notice) My nipple also have a milky discharge. Again I didn't worry about it as I thought it was normal. I don't do this regulary enough for it to be due to stimuli. 

Suddenly last week a cluster of montgommery turbicles adjoining my nipple seemed extr big and as soon as I touched it not even squeeze some thick liquid came out. Later that night the liquid was like a bloody puss. Nothing since then. But now in my upper right quadrant quite deep and definetally not visible I feel like a mass that I don't feel on the other side. It is not hard. It feels spongy I suppose. And now it is tender since I've touched it and I am constantly aware of it. not painful just aware. slightly pulling and if I am not imaging it like a burning feeling? ever so slightly.

I have been referred for urgent screening which is on Tuesday... But I am now so worried with heightened anxiety it is out of this world.

I don't even know what to expect from the appointment. What do they do ? do you see nurses or consultants? 

Anyone with similar issues with montgommery glands and or lump?

Can anyone shed light on what to expect at my appointment? It is a "suspected Cancer - one stop unit"