Hi Junas,
Sometimes it is really hard when treatment has finished to just get up and move on. It has taken over your life totally for a time and just because treatment is finished doesn't mean that mentally the whole experience is finished. Take it steady and If you can find one thing at a time to get back into it might just be the way to go. It can be something small that you used to do and enjoy pre cancer. If that seems to hard then try to find one positive thing out of each day and write it in a book. It can be as small as doing something you couldn't do yesterday like go to mail box or talk to a neighbor, doesn't matter what it is it really just means you start looking for the little positive thing to write down each day, and focus less on the negative, then start looking for two things.
But the important thing to remember is you are NOT alone, many of us have the same issues when treatment finishes. .
Hope this has helped just a little.