Lana Del Rey’s quick marriage to Jeremy Dufrene is nerve-wracking to her inner circle, a source claimed. “Lana is very impulsive, and she’s always had a thing for older men, so in some ways this isn’t all that out of character, but that doesn’t mean people around her aren’t concerned that she’s jumped into this way too quickly,” an insider dished of the singer marrying Dufrene in September after only being together for a short time. “By all accounts Jeremy is a decent guy, but it’s still hard to imagine this lasting long term.” According to the insider, the star, 39, is a “hard-core romantic” …