Lost appetite? Whats going on?

So here's the start of my story, to keep it short...

I was able to eat around an average 2000 and maintain my weight at 110 (after 2 years of a random drop to 100 and struggling to get it back up).  If you are wondering my stats, im 5'3 and small framed and 22.

2 weeks ago I completed a marathon, my weight jumped up 10 pounds in 2 days, horrible water retention bloat.  Some of it has come off though, but fitting into my pants is a pain now.

Now about my appetite....it hit a wall.  I dont know what happened or why or how but it just like...died.  I've been struggling to get myself to eat sometimes, I'm also usually hungry after my runs but since a few days after the marathon its been like...meh not hungry.

And today is even worse because that lovely time of the month rolled around and I know my appetite decreases.  I struggled pretty bad with breakfast this morning (I have an 8 hour shift ahead of me, i need a good breakfast to get me to last til break).

I just need some advice or input on what the heck is going on.  Is it because my 70 mpw got cut back to the normal 45 (even during the 2 week tapering I had no problem with my appetite, i just had to decrease what i was eating back to pre-marathon levels)? Is it because of the weight i possibly gained and my body is like "your going back to normal weight so im gonna kill your appetite."

I'm just confused on whats going on and if ill ever get my appetite back to normal.

Besides the weight gain, are you undergoing any other stress?

Just the same amount of stress as pre-marathon minus school work....which has been replaced by my parttime job, which is way to easy stuff to me (retail past 2 years).