Was JT Miserable With Jessica?

Last we heard on the subject, a source had the following to say about Justin Timberlake and Jessica Biel’s breakup:

“Mila had nothing to do with their break-up. In fact, no one came between them. They decided their relationship ran its course and it was time to move on.”

Looks like we may have some more evidence to suggest that Mila Kunis wasn’t a part of the breakup decision, because according to another source close to JT, he was miserable with Jessica for a long time.
Here’s what the source had to say about it to US Weekly:

“[JT] had been aggressively trying to end things.”
“He hasn’t been happy with Jessica for close to two years.”
“You’d be surprised at how soon the love was lost on this one. Justin said he was miserable.”
“He just said he didn’t want to marry her and it didn’t feel right. It just stung her in the heart.”
“He didn’t admit the cheating, even though we all knew it.”

We’re not 100% sure that we believe he was “miserable” for the majority of the relationship, but clearly things weren’t working out, and as we’ve said before, we’re glad they did the mature thing and acted like adults about their breakup.
Do U think JT was miserable during his relationship with Jessica Biel?