It seems that you and I have more in common than previously thought. My father was the force (and I use the term both literally and figuratively), that kept our family on the straight and narrow. Though I never got along with him, his death...devastated me, drove a wedge between me and my brother. So yes, much like you, the Petrellis really haven't been the same since then.
One promise kept can redeem you, but it must be the right promise. And forget about what the rest of Oz thinks. You love this...Boq, right? He's all that matters, then. His opinion of you and your opinion of yourself are the only two opinions that you should concern yourself with. Don't let others define you. Everyone else is just gonna lie to you, and if you're who I think you are, they're just gonna try to use your love against you and get you to use your powers for their own ends. Trust me. I speak from experience on this.