If 2) and/or 3) need doing, then just doing 1) won't solve the problem and your new chain will get trashed in double-quick time.
Chains are just as much a consumable item as tyres or brake pads and it's a false economy to try and squeeze extra use out of them: see 2) and 3) above.
1) Almost certainly needs a new chain.
2) Probably needs new chainrings.
3) May need a new cassette.
If 2) and/or 3) need doing, then just doing 1) won't solve the problem and your new chain will get trashed in double-quick time.
Chains are just as much a consumable item as tyres or brake pads and it's a false economy to try and squeeze extra use out of them: see 2) and 3) above.