I recommend passing the trinket to anyone else that can use it and continuing to use Frost bomb. There are plenty of trinket alternatives including the DMF trinket, the VP trinket, and once terrace comes out, the one off sha of fear
Personally when someone asks me for advice I'm going to recommend trying to get the best gear that their character can have instead of hobbling their maximum damage potential for pretty much no reason at all.
I would reccomend taking your BiS trinket and using one of the bombs that provide an equal amount of damage to Frost Bomb, thus providing a higher amount of DPS because it allows you to use your best in slot gear.