1996 Toyota Van glow plug light stays on loss of torque

Electrical problem
1996 Toyota Van Two Wheel Drive Automatic

Hi there, I have a toyota estima auto diesel 1996, was driving fine then momenteraly the amber and green turbo lights came on and then the glow plug light and the faulty light, light, the turbo lights were only for a second or two, but now the glow plug light stays on permenantly as does the faulty light, light. There are no issues with the light, takes several seconds to start as if not working off glow plug. Also the torque has decreased dramatically, I effectively have to pull off in low, then to second then in drive, doesnt seem to want to pull off in drive too well. There is also a very minor oil leak ie, a couple of drips now and again staining my drive Any ideas?