Battery is probably cactus
Try jumping off your car / truck battery, engine not running so the starter is only getting battery voltage
If you can pop a volt meter across the battery terminals and see how much voltage drop you get when the engine is cranking
IF it goes under 11V the battery is now toast .
You can confirm this by taking it to an auto parts shop.
Most will pop it on a carbon pile load tester and give you the bad news