Sick dwarf gourami

I’m pretty sure my dwarf gourami has dwarf gourami disease, his spike is s shaped, he has a growth, his tail has started to break away and he’s a bit bloated. He just stays near the surface now or at the bottom of the tank and occasionally swims but will still peck for food and stuff. I’m considering euthanising him with clove oil but I have never done this before and am scared I will do it wrong and not give him a calm send off. What do I do? Do I let him pass naturally or do I try the clove oil :(