if anything vs much

if anything

• Used to suggest or state tentatively that something may be the case (often the opposite of something previously implied). 

• Used in questions when the speaker does not know for sure if the listener will have an answer. 

much

• Used to indicate or compare extent. 

• Often; frequently. 

• To a great extent. 

• Many ( + plural countable noun). 

• A large amount of. 

• Used to indicate, demonstrate or compare the quantity of something. 

• A large amount or great extent.