It's always nice to talk to a stranger honestly, even if it's just on the internet. I can appreciate you sharing your experience with others.
Would it be helpful to challenge your own way of thinking?
It seems like you really struggle with the idea that nothing is permeant. We all know it's a universal truth, but what can you do about it? When you focus on that, it only robs you out of many great experiences and opportunities in life. If you change your mindset and think about what you can do with it, you can take things and embrace them as they are now. Once you learn to live fully in the present, you won't be overly worried about it. Don't make your present suffer due to the past and future.
Btw all our thoughts, behaviors, and emotions are shaped by our internal beliefs. You should learn to question these painful stories you keep telling yourself, because they are not actually true. Some of them are things like "I'm not good enough", "I'm unlovable", etc. Anyway, I believe there are people who will see the good in you. Maybe you just haven't realized it lol