Please help- my heart is broken.

Hello everyone, I’m coming to y’all because I need a different point of view. This is my first serious relationship, so I don’t know what to expect. Love is hard. My bf struggles with depression and has been in a funk lately. Today, we had a convo about it, and he said he loves me but can’t promise we will last forever because he doesn’t know what he wants out of life yet. He also says he’s not going to give up on us, and that he cares and loves me, but that he doesn’t want to drag me down with his depression. Is this normal? We’ve been dating almost a year and somewhat some of the spark has gone away as we’ve gotten more comfortable with eachother. I love him so much, I don’t want him to leave me. Should I be so heartbroken? Has this happened to you before? Please help