yezterday I took my Apple Watch off fully chargered and didn’t touch till 12hours later now a red lightening bolt and the time appears on screen, I’ve tried holding the side button down to restart and still won’t, also chargered it to see if that would change for 5 hours and still nothing ?
You need to charge your watch. I know you already tried so check your charging equipment is working by testing with a different magnetic cable and power supply if you have them available, the power supply from your iPhone charging will be perfect, any USB supply which will connect the mag cable should be ok. See If your Apple Watch won't charge or it won't turn on - Apple Support for more details of how it should work.
If that doesn’t get it working, Contact Apple Support and arrange to have the watch checked by Apple.
Apple Watch red lightening bolt and time
