How to reinstall cydia on a already jailbroken iPhone 4?

Ok I've just about given up on trying to install cydia again
Here's how it disappeared: I was removing some package that I had on there and then it disappeared
Method's I've tried to fix it with:

1.iFunbox and other things like that using the Cydia AutoInstall method

2. I've tried installing mobile terminal using that aswell but it didn't work

3. I can't use the iFile method because I don't have it installed the only app that's left is Winterboard for some reason

4. I've tried doing a restore through Itunes but all sorts of different errors pop up

5. I've tried using the Redsnow jailbreak to reinstall cydia but it come up with an error " Please reboot your iPhone with a clean slide to turn off swipe" or something like that

6. I've tried jailbreakme.com

7. I've tried restoring it with the Redsnow option

8. I've tried using Tinyumbrella

And multiple other methods

Cydia is gone but Winterboard is still there I had a few other cydia apps installed but they all disappeared or they were just tweaks

If anyone has a solution it would be much appreciated thanks

Did you try restoring your phone?
This happens to me quite often too.
But this is how you restore it:
Hold down the home and power button for 10 seconds, after 10 seconds let go of ONLY the HOME button and CONTINUE holding the POWER (sleep) button for 5 seconds.
First your screen will go black, then after approximately 10 seconds the apple logo will appear.
Try this and if it still doesn't work then connect your iphone to the computer and restore it to the latested back up. You will have to re-jailbreak your device unfortunately.