Struggling to Find a Reason to Live Beyond My Partner

The only person or support system I have is my FP, they’re my gf who I’ve been with around a year and a half. The only time I’ve felt true positive emotions and happiness is with them. Which I’m so grateful for… but I wish it wasn’t the only thing keeping me alive. I wish I had motivations and goals beyond just taking care of this one person. They’re the most important person in the world but it’s still upsetting that I can’t find a single other reason to stay on this earth. I hate it. It’s a constant battle between unbearable mental pain and being there to support my gf. Also i should mention that they’re the MOST supportive, kind, loving, accepting person I’ll ever meet. They’re such a great person for my mental health but I feel like all I do is drag them down.