Please help me fiigure out whats worng with my Oncidium :(
 

Looks like it may have root rot that has gone into that pseudobulb. I would gently remove it from its pot and inspect to see how bad the damage is. However, new growth is a good sign, so I would guess your plant is quite salvageable. Good luck! Post pics! I welcome, more experienced growers to comment?

thank you, i will remove it and post new pics!

It does look like a little rot has set in. Keep an eye on how much water you give it. ;)

Watch your water to avoid rot indeed, make sure the plants fed well, give it lots of light, and your oncidium will produce nice flowers.

Bec of the large bulbs Oncidiums can stand quite a bit of drought so underwater is always better as with most orchids. You arent going to kill it not watering it for a few days a week or so to let it dry out some.

If you have active roots you could take that opportunity to change out the media and re-pot fresh in case theres something else lurking down in there that just cutting the bulb out might not prevent or cure.