Alexander Zverev's longtime girlfriend, Sophia Thomalla, recently stunned fans with her new look. The German actress, model and TV personality revealed a dramatic hair transformation.On Monday, Sophia flaunted her golden curls while sitting on a couch in a sleek black leather jacket, light-wash jeans and a subtle black top. Her hair was the main highlight since she had colored it blonde, moving on from her natural brown hair look. She captioned the post:"Someone once said that I look 10 years younger in blonde, so I went blonder than blond." View this post on Instagram Instagram PostAlexander Zverev and Sophia Thomalla went public with their relationship in late 2021. Notably, they have a seven-year age gap (Sophia is older). Zverev has previously admitted that Sophia's presence brings peace and security to his life.The couple was featured in Netflix’s Break Point (Season 2), where Thomalla jokingly criticized Zverev's chronic tardiness.Alexander Zverev felt "alone" and "isolated" at Wimbledon in Sophia's absenceFor the first time in his life, Alexander Zverev is considering therapy following his first-round loss on Centre Court to Arthur Rinderknech in a grueling five-setter. After the exit, Zverev opened up about the loss and how Sophia's absence made him felt "alone" and "isolated.""I feel very alone out there at times. I struggle mentally. I'm trying to find ways to get out of this hole but keep finding myself back in it," Zverev said. “Generally speaking, I feel quite alone in life at the moment, which is not very nice ... Maybe for the first time in my life I'll probably need therapy. I've been through a lot of difficulties. I've never felt this empty before."Zverev further added that he's missing the spark in his life outside of tennis. He added:"Just lacking joy, just lacking joy in everything that I do. It's not necessarily about tennis. Just lacking joy outside of tennis, as well. Even when I'm winning, even when I'm winning like in Stuttgart or Halle, I’d not getting the feeling I used to get, when I was happy, over the moon, motivated to keep going. It's just not there right now for me."Notably, Sophia Thomalla was not in the stands to support him. According to Sun, she was in Germany, filming commercials. Even during the Masters tournament in Rome, where Zverev reached his 100th career quarterfinal, Sophia was in Thailand, shooting Are You the One? However, she was there to support the tennis star at major events, including Indian Wells and the French Open.