What I have figured out is that you really have to forgo your ego and drop the weights so that you can have the mind-muscle connection. Only then you hit them hard.

Exercise wise, you can try incorporating (if you are not already doing it) skullcrushers, close grip benchpresses, tricep rope pulldowns, tricep dips, etc etc.

Bodybuilding.com has a full set of exercises you can have a look at.

I do not really get what you mean as well (bolded)...

Uhm, what I meant was just remember that you are bodybuilding. Bodybuilders are primarily concerned about gaining muscle mass, and aesthetics, and NOT about moving the heaviest weights possible.

Following this logic, for example, for skullcrushers, it would be more beneficial for a bodybuilder to use lesser weights so that he can maintain proper form in order to stimulate the muscles he intends (the triceps in this case). This is compared to using less strict form just so that he can complete the rep.

So do not let your ego get in the way, there is no shame in using lighter weights so that you can stimulate your triceps.

Do not think I'm experienced enough to be commenting on your workout routine though, hope someone else can help.