The media definitely played a role in the election. From one standpoint, hammering home the email crap, and from another limiting coverage of Trump's words and deeds. Also I think damage was done by pundits who generally believed Clinton had to win and didn't convey any other message, so folks either didn't vote or were mobilized to defeat her.
Yes, the media reported on polls all across the country that had Clinton winning. This gave us false hope. We are devastated now because the media showed us that Clinton was in the lead. The electoral votes, however, did not go according to what the media was saying, even though the popular vote did.
The media didn't do a good enough job getting ALL the information out there about the candidates. Certain candidates were allowed to snake through the election with much of the public not knowing some of the facts or not taking the facts seriously enough. Without the media, we cannot easily access the information needed to make a wise, informed decision.
While your opinion may be shaped a certain way if one listens to only one source, I would not generally say the media can be too involved in an election. It is important that the public receive as much information on the candidates as possible. The trick is getting fair and balanced information from a variety of sources and independently researching topics that matter to you.