I think I have completely screwed up. What a fool

[Homesoil]

I feel utterly stupid and quite distraught.
I have had a forum since 2007. My domain expired in 2009 so I transferred it somewhere else and kept it as a read only forum.
I brought it back to life today...I upgraded it with the webinstall thing..worked on it all day changing the style sheet and general tweaking and then I realised I had lost the captcha (or the letters/numbers) on the registration page. Checked out the help forum but couldn't see anything to help me so I began to reinstall certain files that I thought might fix it. (now it is obvious I don't know what I am doing but I have played around like this in the past and always managed to not make any serious mistakes but alas i feel i have now. 
I thought I would reinstall everything and nearly died when the install.php page appeared so not know what to do I thought i would fix that issue by just deleting it. Of course then I got an error saying the website couldn't connect to the database.
So what I did then was go through the install procedure using the original database username and password thinking all my files will miraculously reappear. Of course they didn't and I fear I have wiped them clean.
I feel sick
I don't understand the connection between the website and the database.
Is there any possibility that my files might exist somewhere?
When I originally transferred the forum to a new domain I didn't do it as per the instructions because I didn't understand them.
I just literally downloaded them to my pc then upload them to the new host and change the paths and it worked.
Can anyone help me or do I need to get my head around the fact that over 5000 posts have been lost?

[flapjack]

When I originally transferred the forum to a new domain I didn't do it as per the instructions because I didn't understand them.
I just literally downloaded them to my pc then upload them to the new host and change the paths and it worked.

wait.... if you just downloaded the files there's no chance it would work, because of missing database. did you make a backup copy of the database?

[Homesoil]

I dont know what to say
It did work
I have no idea how
where are my database files? (and please dont say in my database)
if i installed a new version of the smf what happened to all my database files?
i obviously didnt back anything up other than donwloading everything onto my pc

[flapjack]

where are my database files? (and please dont say in my database)

look for a file with .sql (or .gz/.tar) extension

if i installed a new version of the smf what happened to all my database files?

it's gone, unless your host is backing up your files every now and then, you will need to contact them

[Homesoil]

Ok I figured out how to get into phpmy admin and yes there are todays files and nothing much else. I have lost everything.
Did that happen when I reinstalled the new forum?
I believed that if I was putting the same database username and password as before that all my files would still exist.
Can someone explain to me exactly what I have done wrong so I NEVER do it again?

Thank you

[Homesoil]

look for a file with .sql (or .gz/.tar) extension

I found one of those and downloaded Bitzipper to open it but it says there arent any files to extract. is that what I am supposed to do?

[flapjack]

when you installed the SMF again the database has been cleaned, the proper way to handle this would be to use an UPGRADE package

I found one of those and downloaded Bitzipper to open it but it says there arent any files to extract. is that what I am supposed to do?

just import it using phpmyadmin

[Homesoil]

I sincerely thank you for your help.

I tried to import the file. I hit go but after a while it came back with a whole list of errors.

I think I may have dodged a bullet though...
The old database is still there and it has all the files YAY

Im quite terrified to do anything.
I obviously need to back up this database and import it into the other one but that is proving difficult.
my phpadmin doesnt look that straight forward
I need to export right?
can you recommend a idiots way of backing up my database?

[flapjack]

take it easy, the errors are showing up probably due to fact that there's some remains still in the database. check all the tables and "drop" them (it's on the drop-down list in phpmyadmin) and then try to upload it again

[Homesoil]

Phew
I cannot believe I put myself through that.
Thank you once again and sincerely for your help.
I watched you tube video (courtesy of tristan ) which showed me how to export and import.
I successfully backed up my old database and imported it into my new one...its still showing an error connecting to the database but I don't care...
I now have it safe and Ill figure it out tomorrow..... its gone 3 in the morning
I tell you what though...ive had a fast track tutorial about databases and I have learned a lot.
I will NEVER make that mistake again.
Thank you and nighty night *yawn*

[flapjack]

no problem, glad you have it sorted