Not happy with where I’m at in life right now.

As the title says I feel like I’m not happy with my life right now. Just recently had a family member pass that I was close with and it really got me thinking about my life. I have an amazing girlfriend and I have a steady job which I know I should be thankful for but I just am not sometimes. I feel like I don’t do anything besides sit at home. Hobby’s I had when I was younger I don’t find much interest in anymore. Any advice on how to get out of this rut? Will it pass? Or am I the problem? I want to be the best partner to my girlfriend I can be but it’s hard right now. If anyone has any advice it would be much appreciated. Thank you