All of the advice after this post is rock solid. I can only add this: pick up your guitar every day and give yourself permission to play.
I agree. And it's all right - in fact, it's probably better - not to be awesome right away.
I always loved music, but couldn't sing at all. But when my wife and I learned we were expecting a child, I decided that I would sing to our kids every night - no matter how bad I was. I wasn't going to miss that. So, I do. Now that I can play a bit, I play to them - every night. No matter how bad I sound. It's more important that I do it - because it's such an important part of life - than it is to sound great.
I took various music lessons as a kid, and I gave them up. As an adult, I tried again. Here's what I've learned:
1. Now that I'm older, I don't expect to be a prodigy. And I appreciate that skill takes time to develop. So I'm more persistent, and more patient. Result: things that seem impossible at one point become doable over time, and eventually automatic. Then, it's on to the next impossible thing. I've learned that practice really does work, and I trust in it completely.
If it were all easy, hell, everyone would do it, and it wouldn't be a big deal.
2. I do it because I love it, not because it's good for me, or I have to. That makes every bit of difference, and you can hear it in the playing. When someone loves the music, it shows. Equally, it comes through when they don't love it.
3. Just playing has opened my mind to different music genres, and I appreciate music much more now - not just for what it sounds like, but for the skill involved. And I marvel at what it took to have the idea - then to express it so skilfully, both in the composition and in the performance.
4. Even though I'll always have a long way to go, it helps me appreciate my own talent, such as there is, a bit more. I still kind of marvel that I can make noises that, well, sound like music. That's excellent.