fire and suffocation glich

So i was playing a normal survival world. (modded by adding addons) and i found this glitch where you can x-ray using any falling block (that i like to use sometimes)so i was on obsidian trying to see if there was dimonds under the lava or obsidian and then i done it but then i was on fire for some reason so i used my water bucket and i was still on fire (like normal) but i was suffocating and i was trying to mine the block that was suffocating me but it was mining the obsidian around me and not the gravell that was suffocating me