Think about this. If you have a ton of stuff because you were not planning on carrying it, contact
www.expressbourricot.com to take it to Santiago. You have pretty much done the hardest part of the Camino, so think about what you might need to carry with you. Then, take what you need and buy one backpack to share and continue on.
For me, carrying what you need is a very profound lesson of the Camino.
Just today, my daughter called and said, "I keep thinking about stuff that happened to me in my past and I don't know how to get over it." I told her, I felt that way until I walked the Camino with my backpack. At first, it was so heavy and I did not think I could carry it, but by the end I hardly noticed it. I realized from the experience that I am stuck with all of the stuff that has happened to me in my life and I can not change it, however, I can learn to carry it, accept that it is there, and realize that I am strong enough to not let it bother me. . . .
I know, this may seem way too metaphorical for your very real situation right now. However, on a very realistic note, I am simply suggesting that counting on other people to carry your stuff may be harder than carrying it yourself. Practically speaking, you can send what you don't need ahead to the end and then share the weight for the rest of the way.
I wish you a wonderful journey, and whoever suggested the Google translator earlier, had the most practical advice.