I'm 45 yrs old, tubes tied, can't be pregnant, boobs are leaking a greenish/yellow discharge, and sore.
What is causing this?

It could be a number of things.

I don't want to scare you, but for me, at age 32, it was a symptom of breast cancer. Do you do your monthly exams? Have you had a mammogram?

Yes, all the time. And no, too small, they won't give me one, but I have had a lump removed about 14 yrs ago but it was no cancerist

Too small for what? Surely not a mammogram!

I was barely an A cup at the age of 32 and the mammogram did indeed detect a lump which turned out to be cancerous.

Since you do have a history of lumps, cancerous or not, it would be wise to seek medical advice and possibly a mammogram.

Before they removed my lump they did an ultrasound, they wouldn't did a memogram, I don't know why other then they said I was too small but I will have it check out. Thank you for your advice!