Learn Turkish: Lütfen bu dengesiz ve tutarsız tavrından vazgeç. - Please give up this erratic and inconsistent attitude.

The verb vazgeçmek (to give up, to quit) always takes an object in the ablative case (-DAn). In Turkish, you literally give up from something, which is why we see tavrından instead of an accusative object.

Why is it spelled tavrından instead of tavırından?

The root word is tavır (attitude/manner). Like many two-syllable nouns of Arabic origin, it drops its narrow second vowel when a suffix starting with a vowel is attached. Adding the possessive -ın (your) shrinks it to tavrın, and then the ablative -dan is added to the end.

How are the adjectives dengesiz and tutarsız formed?

They both use the suffix -sIz (without / -less). Denge means "balance", so dengesiz means "unbalanced" or "erratic". Tutar means "consistency" (from tutmak, to hold), making tutarsız "inconsistent". These adjectives perfectly describe the behavior of someone who acts kâh öyle kâh böyle (sometimes like this, sometimes like that)!

If the English translation just says "this attitude", why does the Turkish word have the possessive suffix for "your" (-ın)?

In Turkish, it is very natural to combine a demonstrative pronoun like bu (this) with a possessive suffix to emphasize a specific person's current state or habit. Bu tavrın translates more literally and emphatically to "this attitude of yours".