Hayden Panettiere said her inability to tell ex Milo Ventimiglia “I love you” was a major “point of contention” in their relationship. The actress reflected on dating her “Heroes” co-star when she was 18, and he was 29, in a new interview with US Weekly while promoting her upcoming memoir, “This Is Me: A Reckoning,” out May 12. “Every relationship I’ve ever been in, I invested my whole self in,” Panettiere told the outlet. “I saw him as my partner and that it was going to hopefully keep going and evolving and lead to marriage.” Hayden Panettiere told US Weekly that not being able to say “I love you” to ex Milo Ventimiglia was the “point of contention” in their relationship (They are pictured above at the “It’s A Mall World” premiere in 2007). Getty Images Panettiere (seen above with Ventimiglia at Comic-Con 2007) said she felt “uncomfortable” over not being able to express her love for her ex when they dated.…