Q: Did I break my brakes? No pun intended. About a week ago my brakes went from feeling hard to sinking to the ground?

Ok so here is the story. I recently just had complete brake failure! If it wasn't for the e brake I would of crashed pedal went feeling normal then spongy and down to the ground!Within a weeks time. I thought I needed tires and maybe it was a traction thing. I had my front pads done a year ago.Never noticed fluid low. I only recently had to add fluid about 4 months ago .Then I had my rear drums adjusted because I saw my brake fluid was low so I assumed I needed them done. I told by the shop I didn't them.Months later I get them done anyway.Now fast forward about a few weeks later I get this spongy pedal. Suddenly everyday it got harder to stop. I had to start using e brake.Until one day I couldn't stop at all!had a friend mechanic look at it and he says there was no fluid at all and that I had a leak from brake lines. Had it towed to my regular shop, he claims no leaks but instead its master cylinder failing. Who to believe? Brakes lines or master cylinder? Should I get another opinio