I am 42 and had a similar diagnosis back in late Nov 2012. My surgeon was very positive about it being treatable, but that I needed to allow 6 months for treatment and maybe a year to get totally back to normal. At this stage I suggest reading all the booklets and brochures available, but steer away from the internet as its too easy to start worrying about stuff that doesnt apply to you. I suggest taking someone with you to you appointment with the suregon as a second pair of ears, and also write down any questions you have beforehand as otherwise its easy to forget what you wanted to ask.
I had lump removed on 6 Dec and a sentinel node biopsy. They took out three lymph nodes and they were all cancer free. Only an overnight stay in hospital. I recovered well from the surgery with the main issue being the side effects of the anasthetcis which make you really lethargic. My scars are healing up well. At this stage the two breasts look the same size, but they say radiotherapy might cause the one with the scar to shrink a bit. Small price to pay to be cancer free I reckon! The scar under my arm is still a bit tender, but the surgeon says thats to be expected and its subject to a bit more wear and tear from clothes and bras rubbing so i guess it will relieve itself in time.
I dont know if a sentinel node biospy is done as a matter of course these days, but I would suggest asking about it. In my case, as the removed nodes were cancer free, it was a definite advantage. The alternative would have been to have an axillary clearance where they remove all the lymph nodes on the affected side 'just in case'. This has a much longer recovery and higher risk of lymphodema.
Anyway, hope the above info helps. I have just finished chemo, and have strated radiotherapy today. Hope your journey is as smooth as mine has been!
xox Fiona