Water damage

Is it likely that my phone is damaged

Yes, there is a good possibility if water/urine got inside. Slowness is the least of your worries, urine contains electrolytes (salt) which is conductive. You may find that your phone stops working altogether or starts glitching in odd ways.

Is there anyway I can fix it?

No, you will need to replace it.

Water damage does not make any phone to perform slower. What it will do is either completely damage it while it will not turn ON or some functions (hardware related) will not function while others may. It is very difficult to judge the outcome of the damage that may have been done by exposure to liquid. This is simply because there are several variables involved, such as the type of liquid, total pressure, amount of time of exposure etc.

The short answer is that you will not know the extent of the damage until you allow the phone to dry and then operate it. In nearly all circumstances, if there is any liquid damage, then it is permanent.

Axel F.

If it gets dropped against a hard surface such a a porcelain toilet bowl, it can break the seal.

"I checked my LCI and it hasn’t been activated. My speakers, microphone and camera is completely fine as well as Face ID and touch. Does that mean no hardware issues are present?"

Not necessarily, it can take a while for corrosion to start it's effects.

With the LCI not activated is a good sign though, you may have gotten lucky this time.

Call them and ask.