Will not start

Was recently poking around in the engine bay fixing headlight grounds. After re-tightening the terminals, one terminal broke off. I went to a local garage and purchased some terminals which were heavy duty lead ones. I then cut off the terminals and pinned both wires (there are two large insulted copper wires for each terminal) underneath the bolts on each new terminal. They fit snugly around my battery posts, but when I tried to start the car, it would slowly crank. The radio, dash lights, headlights, and horn all work. I tried several times to start the car, and now when I turn the key the car does not crank and it eventually keeps making a clicking noise. I hooked the battery up to a charger last night which showed that the battery was at full charge. The horn does not shut down after constantly blowing it. I was wondering if it could possibly be not enough of the negative ground wire pinned on the new harness, as it may be enough for small appliances but not enough to start the car. Maybe the starter? I will also attach images of the new terminals I put on, and hopefully I can get a video of the cars behavior.