I’m concerned that you are over-eating yet underweight. It’s just possible that at least some of your anxiety is due to an underlying medical problem. For that reason, I urge you to see your medical doctor for a complete exam — just to make sure.
If you are medically fine, then please do see a counselor. The embarrassment you are reporting may be a symptom of social anxiety. People with social anxiety fear the judgment of others so much that they have difficulty in environments (school, job, social situations, even shopping) where they have to interact with others. Many people with this disorder only feel safe when they are accompanied with someone they trust.
The good news is that social anxiety is treatable. There is no reason to live like this. The usual recommended treatment is a combination of an anti-anxiety medication and talk therapy. The medication can take the anxiety down a bit. It should not be a substitute for talk therapy. You need to learn ways to manage anxiety and to cope with social situations instead of avoiding them. No medicine will teach you that.
And this is important: Very few people know where they want to go in life when they are 17. That part is normal. The next few years should be about exploring your interests and passions. Dealing with your anxiety now will free you to do that exploration.
I wish you well.