Newbie help with Rails/Ruby. Totally lost! (Mongrel related, I think) 503 Errors

Hi everyone. I am on the verge of actually hiring someone to fix this
for me, but I hope it doesn't come to that.

I have no experience with Rails/Ruby, but I do know my way around
computers in general.

I have two domains on one server (Hostingrails, I am beginning to hate
them more and more these days).

My secondary domain works 100% fine.

But for the past few days, my primary domain has not been working, it
has been giving me 503 Errors. I've opened a ticket regarding this, and
they told me to SSH into my server and reset "Mongrel". I've done this
using the code they gave me; "mongrel_rails start -d -e production
-p13930"

It seemed to have worked, but the problem was still there. The log says
the error is something about:

"require': no such file to load -- dispatcher (LoadError)"

I've re-opened a ticket concerning this, and Hostingrails basically told
me that it is not their problem anymore and that it's solely up to me to
fix it. Brilliant.

So I spent a good part of the day looking and changing things around
through SSH (probably wasn't the greatest idea) but I still keep getting
503'd on my website.

However, I recently found out that my index file HAS to be index.html,
or it will not render the page. index.htm or index.php will result in a
503. If I set the index page to index.html, it worked. Which is strange,
my htaccess file allowed for all.

Another problem, I think I have inadvertently changed something in my
settings while I was SSH'd in. When I do "bundle install" it installs
the gems into my own private webspace, for example /home/mywebsite. But
I believe on my shared plan, all the rails/ruby/gems etc are all under
/usr/local/rvm/gems/ruby-1.9.2-p0/ which I don't think I have access to.
How do I change the directory to the default one?

I think that's everything for now. Here are the rails installed on my
server by the host:

Installed at (3.0.0): /usr/local/rvm/gems/ruby-1.9.2-p0
(2.3.8): /usr/local/rvm/gems/ruby-1.9.2-p0

(again, I think my mongrel is looking in the wrong place, as my gems are
now being installed into /home/mywebsite/ instead of
/usr/local/rvm/gems/) Is it possible to someone reset the settings I've
changed back into my host's default one?

Would anyone be willing to take the time and try and fix this with me? I
am pretty annoyed at Hostingrails, since I didn't do anything to create
this problem, and they are outright refusing to help me. Why is my
primary domain getting 503 errors when my secondary domain works fine?