How do I stop this?

You would need to set armor to armor+items.armor, since the event is constantly running. Or you can make it a trigger once style event for example 'on drop item' you can put all that logic in a function and run it once.

So i need create variable for item items.armor and set player armor variable as player.armoe + item.armor Yes?

Delete the bottom events for overlap. On your event for mouse click call a function. Create the function below that adds values to the player, like an Add Stats function. Pass through as parameters all the stats like items.crit items.armour etc. In the function set the player stats based on parameters. This means when you click the item and it moves to the slot it will run the function and add the stats, try this.

Thanks lionz for responding, but i fix that with setting value on start = 0

That is not a good fix unfortunately you will run into bugs as you expand the inventory. I've seen the events and what is happening you are setting it back to 0 and then to an appropriate value every tick, flip flopping between 0 and the correct value, it's better to just set it once for simplicity and to avoid bugs. Also you can get performance issues from doing this.