Worsening electrical problems and now engine overheating?

My vehicle listed above is having multiple electrical problems that keep getting worse. The dash gauge dials sweep wildly at times; the headlights, brake lights and turn signals went from dimming to gone completely; the power sliding passenger door and the radio have stopped operating completely; door locks and power windows work only sometimes. I'm thinking it might be the BCM? Also, now the dashboard coolant engine overheating warning light comes on in less than one mile of driving and the gauge dial spikes to above the topmost red line. I replaced thermostat 3 to 4 months ago and it worked well for a while but now the problem is back and worse than ever.