Hi. I'm sorry you are feeling so bad at the moment.
When a family member doesn't believe in, or is ignorant to, the way you are feeling, it can be frustrating. It's also natural to feel sad after a breakup with a person you liked. A lot of people on here, me included, can relate to the way you are feeling - tired and suicidal. You will find people on here going through similar experiences to you, who can help support you through your tough time.
Pets are a great reason to stay motivated, and they can help us greatly, but they certainly shouldn't be the only reason you want to keep living.
Have you pursued treatment for depression before? Depression can be treated through methods such as medication or therapy. If you think either of these might be a good idea, you should visit your doctor. If you don't think your parents would think this is necessary, have you tried telling them how you
really feel? You could try telling them how tired you feel and how you are feeling suicidal at the moment.
As for your life goals, some may be lofty, but don't let anyone hold you back from trying. Even if you don't achieve your specific life goals, you can still end up in a good position. If a person, for example, wanted to become an actor in Hollywood, they may not make it as an actor but they may end up in another career in show business that they enjoy. Your parents were likely just trying to prepare you.
As for the moment, you have found a great space to share how you are feeling and where you can receive some support. I hope you can feel better soon. Sending hugs

.