I am new to endnote and have been using it to undertake a literature review. 

I have over 7500 references and am currently filtering them, but Endnote crashed and closed and since then it keeps crashing within 10 seconds of opening it. 

I have restarted by laptop (Windows) multiple times but to no avail. Can someone help me?

The library is likely corrupted. 

First copy the library and the .DATA folder to a backup location.  Then rename the pointer to the original LibraryName.enl file so  Endnote can’t open it when you run the program and then Open Endnote.  It will say it can’t find that library, then change your “Library” settings in preferences to “do nothing”.  (so it doesn’t crash when it tries to open the corrupt library) and then see if you can name it back the original and use “tools” recover library.  

If you can’t - I suggest you reach out to the endnote.com’s support page and ask if they can rescue it.  Do you have a synced back up in the cloud?  They might be able to help you sync it back to the desktop too.