Reassess your lat strength and rear delt strength.  Often, when first overhead pressing many lack the stability to really drive through it off their shoulders never fully engaging their delts.  Also make sure you’re getting full scapulae retraction.  Assess your bar path and find out if you’re getting too far in front of you (video analysis from the side helps with this).  

Where specifically are you failing?  Bottom end?  Lockout?  A good accessory movement to help with OHP is pressing to the center of your head.  You have to be controlled with it or you’ll crack your skull thus making your triceps having to work that much harder.  Failing off the bottom?  Get some front delt raises in (DB) and again learn to maintain tension throughout.