Do disturbing dreams following the intention for Salatul-Istikhara have a connection to the matter for which one seeks guidance?

The mentioned dream has no bearing on your intention to perform Istikhara; rather, you should proceed with Istikhara, as this dream might be a form of distress from Satan. We advise you to perform Istikhara and proceed with whatever Allah facilitates for you, consult people of sound judgment and advice, and then trust in Allah's choice and be content with it.