In the midst of the worst OCD episode of my life, filled with severe depression, I had a random thought to stab someone I loved. I immediately started crying and I also had really bad thoughts about myself following that.

That is called an "intrusive thought." It is a classic OCD symptom. It doesn't mean you could or ever would hurt anyone. In fact, the fact that it disturbs you means you never would. Just tell yourself, "Oh, that's just an intrusive thought." And try to let it go. If they get worse or more frequent, tell your doctor.