Arriving late into this thread
Vicente, Latin and US cultures view early retirement much differently. Itís possible you are not enjoying enough support from neighbors, friends, or even family. Latin culture (my experience in South America, but directly derived from Spain) views ER by a man as something unusual and not generally positive. At the same time, volunteering is not well established and opportunities are not common. I can see how it would be challenging for you in Spain.
Do you know how to build a website? If not, would you like to learn? Does your town have a website? Learning how to build a website, then building one, is quite an undertaking. Doing one related to your town or region can be of social value as well as personally interesting and rewarding. If your town already has a website, surely it could use some help. Perhaps even photographs.
Would you like to study? The opencourseware initiative lets you access all the lecture notes for classes from universities like MIT from your home office. OCW Consortium
Have you ever thought about creative writing? You donít have to share, but it is something you can do in a structured, disciplined way and also might helps deal with your own thoughts.
You really need to get medical attention for your eyes Ė you canít let that hold you down.