I don't know what is wrong with me

lately, I have been getting a crazy amount of mood swings.  I'm happy then the next minute that can all change- to anxious or frustrated or upset and or feeling tearful.  I've also been lashing out at people and getting frustrated more than I have before.  This all scares me.   I was diagnosed with OCD a few years ago- but maybe I have more than OCD.   I just feel like such a wreck. It's not fun.   

I've been talking to a therapist behind my parents back.   Had my 4th session with her yesterday. Parents haven't found out which is good.  

The therapist and I have discussed some of the sensitive stuff but not as much as I'd like.  The only problem is that I'm scared that discussing it somemore will cause a break down.  That makes me nervous.