As a student, you will be faced with not only storing your own writings, but storing other information (articles you read, graphics, web links) as well – and in a meaningful way that allows you to later find what you know that you already know but can't quite remember.
Many academics use information management solutions (see also: Personal Knowledge Base) such as DevonThink. A Google search brings up many pages where users explain how they work with this or similar tools.
The advantage to a tool like DevonThink is that it analyzes the content of the documents that you store in its database (it even "reads" images with text and PDFs), allowing you to find relevant content through a keyword search. DevonThink is extremely powerful and I find it quite useful in an academic writing context, where projects are not closed after completion, as they are with novel writing, but material and knowledge keep collecting and stay relevant for all your writing life.
I simply drag and drop everything that I read into DevonThink, from web pages to journal articles to my own essays and blog posts. Sometimes I make the effort to add keywords manually, but most of the time I just drag and drop documents on the DevonThink interface. Later, when I have to write a paper on a specific topic, I first go to DevonThink and see if I have already read something that is relevant to my current project. It is like a machine searchable memory for me.
Of course you will have to write your texts in another text editor, but the advantage to this is that you can use any text editor you want with the functionality that you find most productive, and don't have to write in a tool that might be good for organizing but has a horrendous writing environment.
As for your needs, DevonThink displays a list of all content that you can sort by type, title, date, etc. You can add tags/keywords to entries, group them, etc. You can access the content directly from DevonThink or open it in an external editor or viewer.
DevonThink is the only such tool I know, which does not mean that it is the only one or the best, just that I use it as an example for the kind of tool I think might be useful to you.
The only recommendation that I would like to force on you is that you think of finding a solution that works for you until you have written your dissertation. At the moment you are a student and think only of getting this semester's work done. But you may decide to get a Ph.D., and you are now already, every day, reviewing lots of material that when you sit down to write your doctoral thesis you will wish you knew where you read what you vaguely remember. So do your future self a favour and start organizing your knowledge right now in a way that will work for you in a few years when you approach the most difficult phase in the life of most academics. This solution does not have to be DevonThink, just decide from the perspective of maybe one day writing a dissertation. (And don't use solutions, like Google Docs, that you cannot be sure will still exist in five years. Google is famous for closing services.)