Sorry you are going through this LGF.
I can give you info. about the breast clinic, so you know what is likely to happen.
You will see a consultant who will examine you, if they think tests are required they will send you for a mammogram and possibly a biopsy. mammogram - they put your breast between two plates so they are rather squashed and take a type of x-ray - slightly uncomfortable but pretty quick.
Biopsy - you will have a local anaesthetic, then they will remove one or two samples of the lump - this feels like a bit of pressure and pulling, but is not too bad. You will be a little bruised for a few days afterwards.
Sometimes they also do an ultrasound of the area.
You will be called back for the results in about a couple of weeks (depends on the hospital but I don't think it will be longer than that)
Remember lots of breast lumps are not cancer, but it's always good to have them checked out for your own peace of mind.
BC is a very treatable disease nowadays, there are more treatments coming up all the time, I was diagnosed at 48 and am now 51 and still here 
If you want a chat, hand holding and support or info. do pop over to the tamoxifen thread - we are all at various stages of treatment and might be able to help with any questions you might have (lots of the ladies who visit the thread are like you at the waiting for a clinic appointment stage).
I'm sorry about the other problem - it must make the health problem hard to deal with when you have that on your mind too.
It is hard if you know people who have died from BC, I do too, but I know a lot more who have survived - it's a serious illness but it's one that is treatable.