iPhone 3G Jailbroken but no Cydia

[JustMyAlias]

I used sn0wbreeze/ ios 4.2 to jailbreak my phone.
Then I used whited00r/ios 5 (really 3.1.3) to jailbreak my phone.
Then I got an AT&T carrier unlock, so I tried to restore my phone.
I didn't know my baseband had been upgraded to 06.15, so I could not restore it.
After various errors, I was finally able to jailbreak it again using whited00r, but now I don't have Cydia on my phone.

2 questions:
1. Am I, for now or forever, stuck with this jailbreak, because of the 6.15 baseband?
What does flashing the baseband do, and would it enable me to un-jailbreak my phone?

2. How do I install Cydia on my phone now??

TIA!

 

[h2olover1]

I used sn0wbreeze/ ios 4.2 to jailbreak my phone.
Then I used whited00r/ios 5 (really 3.1.3) to jailbreak my phone.
Then I got an AT&T carrier unlock, so I tried to restore my phone.
I didn't know my baseband had been upgraded to 06.15, so I could not restore it.
After various errors, I was finally able to jailbreak it again using whited00r, but now I don't have Cydia on my phone.

2 questions:
1. Am I, for now or forever, stuck with this jailbreak, because of the 6.15 baseband?
What does flashing the baseband do, and would it enable me to un-jailbreak my phone?

2. How do I install Cydia on my phone now??

TIA![/QUOT

Go to the DevTeam Blog, there is a new way to downgrade 6.15.00 baseband

 

[JustMyAlias]

Thank you!

And I just realized... I do have Cydia (though I can't seem to connect or download any apps right now) - it is under the AppMarket with whited00r.
Oops

 

[zig9449]

Cydia must fully load before you can install anything.

Tap Changes> Refresh button in the top left corner....and wait for Cydia to fully load.

It takes some time...but it only takes a long time the first time you do it.