Your post doesn't seem to have an issue with passive voice. Passive voice doesn't have anything to do with run-on sentences, though.
A run on sentence is one where two or more independent clauses are joined together without appropriate punctuation. They can occur in both passive and active voice sentences. For instance:
My dog is a terrier she always digs holes and barks.
This is a run-on because you would need a semicolon between terrier and she, or a comma and coordinating conjunction. Both clauses are also active voice.
Passive voice has a place in fiction. It's something you'd use when you want to emphasize the subject of a sentence as the recipient of its main action.
But if it's overused, it makes for indirect, cumbersome prose.
By the way, the italicized clause in the previous sentence is passive voice. The test you can use to check if a clause or sentence is passive voice is if you can add the phrase "by zombies" to the end, and it makes sense, it's passive voice. Sentences can be a mix of passive and active voice too.
So some examples of passive voice sentences:
He was dragged to the dungeon in chains.
"He" is the subject of the sentence, but he is the recipient of its main action. Who or what is dragging him? We don't know. But we could add what is dragging him if we wish. By the guards, or by zombies
An active version of the sentence would have to include the entities doing the dragging:
The guards dragged him to the dungeon in chains.
Here's a mixed sentence:
Thrown from the horse, she hit the ground hard.
The first clause is passive, but the second one is active.
Now to change the two examples into active voice, you'd have to include who or what did the action.
So:
The horse threw her, and she hit the ground hard.
The only suggestion I can give you for catching excessive use of passive voice is to put what you've written aside for a bit and come back to it. Or try reading your sentence aloud. Sometimes these techniques can make it easier to get that distance you need when editing. Mistakes won't cripple your novel unless you fail to catch and fix them when you revise, rewrite, polish etc.
Here are some links about passive voice and about run on sentences:
https://owl.english.purdue.edu/owl/resource/539/01/
http://www.quickanddirtytips.com/education/grammar/what-are-run-on-sentences