Will becoming muscular give me more attention from girls and help me get over my ex?

me and my girlfriend recently broke up, she was my first one ever. She is really cute. After the breakup my self-esteem went down a lot and i don't feel like im that attractive to girls. She started acting like she wants to make me jealous an tries to make me miss her i guess by trying to look her best. And it hurts me i know that i gotta be a man and suck it up.. im trying. Im 18 ,6 feet tall and really skinny, 135 pounds. I was thinking about starting to workout, like eating alot an lifting weights. Is becoming muscular going to get me more attention from girls? I know that i wont become self-centered after becoming muscular still gonna be sweet and humble and nice. I think that it will also boost my confidence especially if i start to get attention fom nice girls. Please give me advice? Should i do it ? And if it will make me more attractive to girls. Its really hard to get over my ex too coz i see her every week.. and she just makes it so hard for me by looking all cute.. flirts with guys in front of me and stuff.. :(