(adsbygoogle = window.adsbygoogle || []).push({}); So, I downloaded 2 tweaks..
And now I have this constant reboot problem.

The tweaks I downloaded was:
HideMe8 Lite
&
Slide2Kill8 Lite

When it was done downloading it told me to restart..
I restarted and now it goes to a constant reboot....

Apple logo - > black blank page then repeats constantly.


I can go hold the power button+touch i.d. and it does go to a black screen but after I turn back on it repeats its process.

How do I fix this problem?

*It didn't even put me in SafeMode .-.

and my phone is starting to over-heat.

Have You tried starting the Phone with the volume button pressed as well?
Testing edit

Disable all tweaks. To do this, turn your phone off, and while turning it on, hold down the volume up button. Keep holding it down until your phone turns completely back in. It'll be in safe mode and you can go into Cydia and do trial and error to see which tweak is the culprit.

if you have updated to the latest cydia you will not have the boot logo problem anylonger. If you cant get in safe mode you will have to put in DFU mode and restore. It has went in this loop because you had a password on and it couldn't process again.

BACKUP AND RESTORE ON 8.1.
I had the same problem on my iPhone running on 7.1.2. every time i unlocked it, it will reset. But then i restored and downloaded a 7.1.2 ipa. Then installed that and jailbroke again and then it worked. And you might know this but before downloading sources you should search them to see if they are legit