Hi Abdul, the first thing NOT to do is panic! Collect your thoughts and analyze the problem. A huge component to architecture is learning how to problem-solve. Try doing some bubble diagrams to get a feel for what types of spaces you need to design. You don't necessarily have to know what they are going to look like yet. Just get a feel for what needs to be accounted for and programmed (i.e. number of rooms, lobby space, laundry room, housekeeping space, front of house, back of house, etc.) Next, I'm not sure what your concepts are or what year you're in, but try keeping the form simple if you're having trouble with it physically. If you have problems sketching ideas out, take what you think is your strongest concept and build some sketch models out of chipboard or something cheap and that you can work with quickly. This helped me out tremendously when I was in school. Remember that the site and context of the project should always be in the back of your mind when thinking about the concept for your design. Is it located in a city or the country? Does it overlook a lake or body of water? Does it sit on a hill or is the site flat? These are some of the questions to think about that could impact your design. Finally, nobody is going to really be able to tell you exactly what to do. Many architects have differing opinions, philosophies, and styles when it comes to design; so there isn't going to be a "right" answer. Whatever you decide to come up with, make sure you believe in it, and pursue it with passion! Hope this helps you out a little bit and best of luck!

plans or photos would help us to understand the space you are dealing with

Any style you like about your neighbors' front door?

You must mention the details regarding your flat and post the plan for the same.