Sorry, really need help! Cannot turn phone off. Bootloop. Bricked?

I had to make a thread, trying to get help. (im a noob)

I think i installed dualrecovery twice. The phone was rooted and bootloader unlocked. I could not get into recovery mode so i, foolishly, installed recovery again.
After that, this xperia z3 is in a bootloop. It goes to sony screen then turns off and repeats rapidly. It heats up if i let it go too long.

I tried holding the volume and power button, it vibrates 3 times, but continues the loop after.

Anyone know of anything that can fix this, maybe if i can turn it off, i can flash firmware? Is it bricked?

Thanks for any replies, very much appreciated.