Hi Lindsay! I'm also 22 and have been living with anxiety & panic since I was a young child. I can relate to how it feels to miss out on experiences that everyone expects you to have in your teens and twenties. Because I haven't experienced a life without A/P, I've come to accept this is 'normal' for me and tried to build my life around it the best I can. One of the biggest fears that can hold us back is having a panic attack in public or unfamiliar surroundings. I force myself to measure achievements in terms of the big picture, so if I have less than a certain number of panic attacks per month/year then I'm proud I've made progress. Even if I have an attack on the bus or at uni I remind myself that I can survive this because it's happening less frequent than before anyway!
I think another key to gaining control over your life is to focus on positive things that are completely unrelated to A/P. The more you define yourself by A/P, the more it remains a presence in your life. Aside from letting you momentarily forget about A/P, hobbies and interests get you out of the house. (Sounds awful but I find them a lot more effective/therapeutic than loved ones...going somewhere with family is usually so laden with stress that it makes my A/P worse!) Try to find an area that you love, and that you have complete control over (a hobby, TV show, author). The more you get immersed into it, the urge to go out or meet people with similar interests will begin to override anxiety.
Control is another issue that affects my A/P a lot. I like knowing exactly what I'm going to do for the day so I feel comforted by the predictability. If you're finding a certain situation stressful, try visualising exactly what you're going to do. Don't take on too much at once, and look forward to 'rewarding' yourself with being able to return home by a certain time. You may also consider taking medication or herbs (if you're not doing so already). Because A/P is quite emotional-based, the knowledge that you're actively doing something to fight it often makes it better (in addition to the actual medicine, so it's a double whammy!)