Anxiety Support Group
Anxiety is a physical condition marked by intense and persistent feelings of distress, fear, angst or dread. General anxiety caused by routine day-to-day stresses usually passes quickly and is experienced by almost everyone at one time or another. However, such feelings that linger over time and are very difficult to cope with, and which lack a clear cause, may indicate...

sharing the details of those lingering anxieties in a safe place such as this one is my most effective way of breaking them down into manageable chunks.
listening. . . keep venting. . .
Keep writing it out and vent!!!
I'd just say try to settle down, find some things you like. Just do the best you can. Ultimately if you and your fiance weren't getting along, having some inconvenience for some months is better than being with the wrong person for the next 20 years.
A couple of suggestions - the words we say to ourselves are powerful. Instead of saying "since my fiancee broke up with me", say to yourself and to others "we are broken up, and it was the right thing to do for me." The first sentence will keep you stuck and feeling like the victim. The second sentence is an example of taking back your power.
Another new thing I do is to be my own cheerleader! LoL. If I get some things done that day, I'll say "Good job" to myself. I acknowledge how much I accomplished that day (can be small things too, like I took a shower today, I made myself a yummy lunch, I cleaned up part of the living room, I made that phone call I've been needing to do..... etc). And give yourself credit for doing something productive! It's a new thing I've been trying, and it doesn't hurt :-)
I was wondering if you had thought about talking to a therapist? You have been dealing with a lot, and talking to a therapist can be helpful. I talk to one for my anxiety. I also find lots of helpful free videos on YouTube for breakups, anxiety, being more positive and productive, self help, etc. You could look on YouTube and find some stuff to distract you. The baby animal videos are darn cute to watch, too! LoL.
We're here for you.... keep writing.