Editing for index page has disappeared

I've been editing my site www.meridianacademy.org these past few weeks. I've add some custom javascript and css and now when I went to work on the new index page I seem to no longer be able to edit it. I know that custom code can have this effect, but does this mean I have to remove the code every time I want to edit the page or can someone see something specific I can adjust? Thank you!

I'm having the same problem! I contacted support about it yesterday but I'm waiting to hear a fix for it

I'm having the same problem! I contacted support about it yesterday but I'm waiting to hear a fix for it

Remove the code and see if the issue resolves itself. If it does, you'll need to fix the code before you add it again.

If the fault persists when there is no code installed, contact Squarespace Customer Care. You can reach out to them here.

Thanks @Paul2009--I removed code chunk by chunk and found that the culprit was

squarespace:script src="plugin.js" combo="true"squarespace:script src="site.js" combo="true"

which I had injected in header and footer in order to run javascript.

Now I've only got

script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"

to activate javascript and things seem to be working fine.

Any thoughts on where not having

squarespace:script src="plugin.js" combo="true"squarespace:script src="site.js" combo="true"

could cause problems?

How do you solve this if the code that is "breaking" it all is actually within the same page you are unable to edit? 
That seems to be the case for me, but since the Edit sidebar is gone, I can't get in there to delete the code (if that is the issue at all)..