Anger outburst

I didn't get my driver's license in the mail because USPS is seemingly wanting to return things to sender, absolutely at random. The thought and actions of having to try to work with the USPS, and dealing with being put on hold for over an hour somehow set me off and I got unreasonably angry at the situation and threw my phone, which ended up breaking it... (tho it took that to break ti after owning it for 5 years, heh). I vented like I used to do back when I played aggravating games and overall made an ass of myself, especially to my wingsister. I feel absolutely awful about it because it... is uncharacteristic of me these days to get angry like that, to lose my temper. I'm not sure what's up and I hope the old anger issues are not making a comeback. It's been years since they existed and I want them to remain gone... I'll make more note of this to my therapist and have my hormone levels checked in turn.