low pressure

Here is my issue. I had some broken pipe because of the cold winter. i cut them back and crimped them off until it got warmer. The pipe were the hot and cold to my master bathroom. I Repaired the pipes but replaced the middle section with half inch pex. So it copper to pex back to copper. the only change now is I added a T to the cold water for my fridge. All my connection are done with sharkbite. the shower and toilet are first in the run and they are working fine. my sink of the other hand has very little pressure. what could have happened?

Try cleaning the aerator on the faucet.

wow that was too easy. I'm on on a well i have black water (dirty) everytime I turn the water back on. is that normal?

No that's not normal . You need a carbon filtration system installed in you're home . As well as replace the well inlet filter

It is normal if your have sulfur which many wells do. The sulfur may not be bad enough that you can smell the gas, but it can still coat pipes. Dropping the pressure and allowing a little air get into the lines will help break some loose and your water will be black for a while. It's not harmful, just unsightly.