Breathing does not create Carbon, it is only transformed.

There are basically 2 pools of carbon. The carbon already in circulation in the athmosphere, plants, animals and so on, roaming at the surface. That Carbon can be CO2, or other mollecules, but there is always a fixed amount. You breathing is simply borrowing the carbon for a bit and putting it out again in the air when exhaling.

The second pool is carbon locked away in the ground, as coal, oil and whatnot. That carbon is OLD and is not supposed to be in the first pool. When you burn oil, the carbon from the 2nd pool ends up in the 1st one. You cannot really offset it because even planting trees just transforms it as wood for a bit, but if the tree burns or rots, the carbon goes back in the air. The only option long term is to send the carbon back in a locked state in the second pool.

But for you, just reduce the amount of carbon you move from pool 2 to pool 1 to help the earth. Cut on oil, gas, coal as much as you can. The rest is basically irrelevant.

You can compare it to the water cycle. You are at a lake with a pump, and pump the water from the lake back into the lake. You can keep going forever and will not cause the lakes to rise since the water is pumped from there anyway. BUT, if a mega corporation starts pumping from underground sources and dumping it in that lake, it would overflow for sure. And they would blame you for all the water you are pumping.