This is more common than you might think. Many people who have a high level of anxiety start to be anxious about being anxious. It can be immobilizing. You shared that you have some tendencies toward obsession so it makes sense to me that you are now obsessing about the effects of anxiety on your happiness.
You say you’ve been suffering since you were a teenager. What you don’t mention is whether you have gotten any help. If not, I highly recommend it. If you could resolve your anxiety by yourself, you would have done so long ago. There is no need to continue to suffer like this.
First, see your doctor for a thorough medical check up. Sometimes this kind of anxiety is a symptom of a medical issue. You want to be sure that you are physically healthy. If you are physically fine, then it’s time to seek out help from a mental health professional. There are well-established treatments for the kind of symptoms you are reporting. Working with a therapist will help you reset your level of anxiety to something more manageable and learn new skills for coping so you can enjoy the pleasures life has to offer.
I wish you well.