My nexus get bootloop in every moment topic

Today my nexus 5 is broke.
Few minutes before all warking perfectly. I've got a RASTAPOP and elementalx kernel of course overclocked.
At no my nexus doesnt response to power button :( but when I connect charger or usb with pc phone was start booting and switching off after one second. Two seconds later it starting again and turning off automatically. Thats happening continously until I dont disconnect the cable.
I tried to go to bootloader then recovery but It isn't possible. Every time I saw the bootloader screen phone reboots itsel again and again and again.

It isn't standar boo loop becouse I have multirom and I dont even have posibillity to choose any rom.

Few weeks ago I bought a cheap battery case. And I saw it doesnt charge battery as ussualy. It charge battery for minute or two then disconnect for while and charge it again diconnect and charge again. Looking like my boot loop. I thing this battery case can broke down my battery in nexus 5 so I order the new one few minutes ago.

Anybody have another solution?

You can be sure Im very sad at this moment.