I hope alls fine with you,
In your research methodology section, explain whether it is going to be qualitative or quantitative, triangulation or content analysis
Your problem statement indicates that you plan to infer the effect/influence of social media on the Brexit vote. Generally when you need to investigate the effect/influence, it has to be quantitative, which means you need raw data which you would then analyse using software like SPSS. However, I see that you plan to only do library research which in your case appears to be primarily content analysis. You would have to clarify this as secondary sources that you would use for content analysis per se is not -data-.