You are welcome cptsdwhoa.

Personally, I think your goals are beautiful!

"It's just that my grandmother has a way of crushing my dreams and goals. I try not to let her get to me anymore, but that doesn't work all the time. I think she means well when she offers her opinion, but boy-oh-boy do I feel hopeless afterwards."

This is an important observation. Would you consider not sharing your dreams and goals with your grandmother? Perhaps don't mention them. If she asks, change the topic to something less deep/important. if she pushes, just calmly say something like "I'm not going to discuss that." And then move on to something else. She's unlikely to change, right? So maybe you can change how you interact with her? She likely does mean well but this interaction is hurting you and you've had enough hurt I'm sure. Maybe give a new approach a try. It sounds like you have other people in your life who share your optimism. Maybe you can keep your dreams and goals nice and safe and only share with those folks....like precious secrets you want to protect?

I'm trying to learn to think of failure in terms of I just learned what not to do...I didn't fail.
Another idea for you. What if instead of thinking of failure, you think of disappointments? As in 'I tried that and it didn't work out and I am disappointed. And that's okay. The disappointment will fade.'

I'm working on believing that I DO have value.
This is excellent! You are working on it therefore you are farther along toward happiness than you may even realize Do you say it aloud to yourself? Try that. Each day somewhere safe, in a strong loud voice 'I am a valuable being in the Universe. I deserve to be happy and well. I am happy and well. My future is bright!'
Mind, body, and spirit respond to messages like that. They also respond to the reverse....the negative messages of depression but then you already know that

Keep going! You are stronger and wiser than you give yourself credit for. Peace and hope to you