looking for a room or one room flat (aprtment)

I'm a 51y lady who is going to work in Charite hospital Virchow campus as a scientist. I'm looking for a room or 1 room flat around Wedding Berlin or within 3 subway stations to Charite hospital Virchow Campus. The rental time is from the middle of April 2017 and it is for long term renting. The rental should be better around 300-450 euro/month including all (furniture, electricity and water fee). I'm from China, as a medical doctor worked in Beijing for more than 20 years and have been working in Singapore as a scientist for more than 8 years. I married and have one boy but I'm going to Berlin alone first. I am an non-smoker and a quiet woman. I do not have any bad habit. I like reading, enjoy music and traveling during my spare time. I can accept stay with landlord in different rooms in a flat (share the public area).