Swedish freelancer seeking one bedroom apartment

I am a clean, responsible 30 year old Swedish freelancer that am looking for a one bedroom apartment to call my home. I am in search of an old flat with one big spacious room where I can make a sleep/living/work space in one. Most desirable areas I am looking to live in are Prenzlauer Berg, Gesundbrunnen and Wedding. Flat does not need to be in top condition as long as electricity, water and gas work without any issues. I'm a big fan of old, charming mid-century flats. I love decorating, organizing and to put my personal touch on my living space. I have been renting rooms to live in for the last 12 years - I always pay rent and bills on time - and am looking to live alone finally where I can keep it as neat and clean as my high standards require.