if only vs though

if only

• Even if for no other reason than; only just. 

• Used other than figuratively or idiomatically: see if, only. 

• I wish that; signifies a wish or desire for the present or the future. 

• I wish that; signifies a regret about an action in the past. 

though

• Despite the fact that; although. 

• Used to intensify statements or questions; indeed. 

• Despite that; however.