i ask myself the same thing sometimes... although i have experienced some rather tragic scenarios that i wont go into detail over of course...
but i know that even what i experienced... others have experienced worse - and i feel bad for not being stronger all the time... but i can't help it - its not something you choose.. but its something that seems to choose us... and sometimes once it takes hold - its so hard to get rid of, because your entire life perspective changes... the way you see everything - changes...
you just have to remind yourself that you are not actively chosing to feel those things... work towards what you desire...
it takes a lot of work - but it is possible... i have heard a good number of people able to do it...
stop blaming yourself - attacking yourself does make things worse... i do it alot and know all about it...
as long as you are doing what you can to improve these things.. you shouldn't feel guilty - even if you arent doing what you can... sometimes when you feel these things its hard to do anything - much less life changing things..
so dont feel guilty - alot of people feel those things... and its not your fault...

stay strong...