Hello Ann
Bilateral galactorhoea - discharge from the nipples - can be caused by a raised prolactin level. I think that it usually presents as a more milky sort of discharge - I have had this in the past.
I really think that you should see your GP ASAP.
Although that you have had the lump so long - it is important to have it properly assessed, and until you do, you won't be able to rest.
It may be an endocrine problem, but even if it is, it still needs to be examined by an expert.
I entirely undestand that you would feel reluctant to go to a GP, especially if you have been told that it is nothing, and that 'lots of women have breast discharges'.
I do not think that that is true.
I am not an expert, but I am a retired doctor, who anaesthetised patients for breast surgeons and a plastic reconstructive surgeon, so still remember a fair bit about it all.
Also - I had two breast cancers last year (I was 52) - the first was picked up on my first routine mammogram, and the second from the tissue removed from the first cancer. I had no symptoms at all at the time, apart from a feeling of uneasiness, that I couldn't account for. It went away after the surgery - so although it isn't scientific, I would recommend that you listen to your body.
It concerns me that you have a lump in your armpit. It could be the result of infection (which would go with the tenderness and muddy sort of discharge that you describe), or it could be more sinister.
I wish I could reassure you more, but it seems to me so imprtant that you see a breast surgeon as soon as you can summon the courage to go to your GP - you really MUST do this.
Ther may be a 'walk-in' clinic in your area - have a look at the website of your local hospital.
I found the people at https://www.breastcancercare.org.uk/ brilliant, both for advice, and for being able to let of a little steam. The people who man the phones during office hours are super - almost all of them have suffered from breast cancer, or have a partner who has. They have a huge level of knowledge, and I am sure that they will give you great advice.
So, please bite the bullet, and see your GP.
Also, please let me know how you get on - I shall be sending you positive thoughts, and sending all good wishes.
Manda x
PS - if the worst comes to the worst - the surgery for breast cancer is far less radical than it used to be, and the adjuvant therapies are finely tuned. One thing is for sure - if it is somehing nasty, then the sooner it is treated, the better for you.
Mx