Some of you like myself may have gone through this issue. I was about to say screw it with the jailbreak but after researching found a fix

Firstly Make sure everything is off, reboot phone, open up the electra app turn off tweaks and click jailbreak, if it doesn't work keep trying till it does, you'll know it's successful when Cydia doesn't crash when you open it.

Now go to your installed tweaks and delete the one you think is causing it, I ended up deleting all the tweaks I installed, after you've got rid of the tweaks reboot the phone.

Repeat the jailbreak process with tweaks on may take a few try's for me I kept on my data and worked fine. You may run into some errors like exploit error jus close electra and reboot phone and try again and voila if done successful Cydia won't crash when you open it.
IF IT DOES YOU DIDNT REMOVE THE TWEAK THAT CAUSED IT

Hope that helps