I've been in a rut and am closed off &amp; dismissive to friends when they ask 'what's wrong/how are you,'....how do I apologize? 

One instance was at the bus stop, another was seeing them at 24 hour fitness. Both times they tried talking to me and all I could muster was hi, then I walked away.

I've been overwhelmed lately between work, personal life and just 'dealing' with life.

I know it's an asshole move but I don't know how to make amends besides texting them an aplogiy. Even then, it feels like I fucked things up by trying to sort it out/wallow (to get it out of my system) when they (inadvertently) snap me out of it when I just want it to pass by fully immersing myself in whatever shifty state I feel.