Can you please attach a link to the page?

It could be that the page has a javascript or PHP error.

www.nicholasjean.com.au

can anyone help?

You need to provide a lot more detail.

Are there Javascript errors in the browser when you try to edit? If so, what are they?
Have you tried another browser?
Did you install anything recently?
Do any updates?
Can you log in at all?
Can you get to the Dashboard?
Is it all pages, or just some?

I have tried several browsers. Nothing new on my computer. All of a sudden the edit button is gone and i have a half finished page that still needs ALOT of editing. I am new to all of this and have no idea what to do to get it back

i can log in but when i go to my project page and the page loads, the edit function is no longer there

When you visit this page and it doesn't allow editing does it have the top grey bar displayed (but with no buttons), or does it simply look like you're not logged in?

If you've got caching enabled, maybe disable it and see if that makes a different (in particular full page caching).

By installing something, I meant did you install any new add-ons to your site?
Did you add something to the page before it started happening?

when i visit the project page and click on the link, it goes to my page and it just loks like im not logged in.

I haven't recently added any new log ins.