Stop buying things till you find the problem. You have an ignition problem. ie weak spark. The battery has run dry. The electrical generator, whatever we call it, alternator, dynamo,magneto is not generating. You measured it. All the electricity on the bike comes from this source. Some is stored in the battery and some goes to the ignition and accessories on the bike. Either the generating system has failed and fried the battery or the battery has expired due to neglect, ie not checking fluid. Simply replacing the fried battery may result in having two fried batteries.