Scared myself today

I started this battle with Agoraphobia about two years ago.  I am what most would call "a nice guy."  I go out of my way to treat everybody with respect.  I am normally good-natured to be around despite my anxiety.  Today though I just was not me.  I was p****d off for an unknown reason. I mean red face out of control I want to punch somebody and kick my dog anger.  I don't understand where this came from, no recent med changes or anything like that.  I ended up just locking myself in my room until it passed.  I wish I had a punching bag or something to let it out.  I have no clue where this came from except perhaps frustration of the slow progress in fighting Agoraphobia.  I have been pushing my limits a little harder lately, exercising more, riding bike and going longer distances outside.  As a result of that my anxiety has increased and my sleep has become more erratic.  But anger towards people, things, and animals are new to me.  Perhaps it's just jealousy of people that don't seem to have a care or the simple life of a pet that does not have to worry about anything.  I don't know is the thing but I never felt this way before and it scared me.  Anybody experience this?

Could you be letting your emotions pent up, and not venting them out? May be they just need an outlet, and when they are not getting that, they are erupting like this. 

Yeah, you got a point.  I am an old school guy that always tries to keep a cool composer and showing to much emotion is a sign of weakness.  I don't even know what an outlet for emotions would look like.  Looking back my son did something stupid and the Police showed up.  Had a bunch of other stressors that day too.  I have always hidden my bad emotions and would just go out and do something to get my mind off things.  Go for a car ride, swimming, whatever.  Now that I have Agoraphobia I am just stuck here with no way to escape what is stressing me.