Headache while allowing emotions

I am struggling to actually feel my feelings, especially around the thought “I hate myself” and other thoughts along the same line. I’ve been trying to access the feeling for a long time. This morning, I noticed when I try to feel the feelings around this and other similar thoughts, I just get a headache. I’m wondering if that’s my body’s way of dissociating or distracting myself from actually feeling. Or perhaps I’m resisting the feelings and that’s why I’m not accessing them. I feel a tension in my head, neck, and chest. I tried to breathe into it but the headache is distracting and my focus ends up in my head. Any suggestions?