You're correct. There was nothing organized by anyone else. Infact, Preperation for the trip took about as long as the trip itself... Planning and prepairing was actually fun, and taught us quite a lot.
As for medical supplies, we had a pretty extensive kit with differant types of relevant antibiotics for differant illnesses, bandages, IV needles, sutures etc. A good book for trips like these, (and just in general) is: "Where there is no doctor - A village healthcare handbook". It describes pretty much anything and everything you can catch in africa, with appropriate medicines and doses to use etc. It also has pictures, which helped us when we got intestinal worms and had to find out which type they were... That was the first time we had to go to a hospital, since we didn't have what we needed, and some worms can eventually enter the brain if not dealt with. The hospital on Ila de Mozambique (north Mozambique) was a little difficult for us to find cause it looked like just another deserted ruined building on the outside... We passed it several times before catching on. When we eventually got into the doctors office we encountered the language barrier as we don't speak Portugees, and he spoke no english. The book was great then to point out the specific worm to him! The blood all over the floors and ceilings wasn't very nice though...
We did however get a laugh over the 12 inch black dildo which he obviously used to demonstrate condom use with! My wife teased me that I would become depressed with an inferiority complex from seeing things like that!