I agree that thyroid disease does not rule your life. I had my entire thyroid removed 5 years ago after cancer and I'm living just fine depending entirely on the thyroid hormone pills. I think one of the keys is educating yourself about your condition. You should know if you are hypo or hyperthyroid and what that means. (If your TSH was 8.2 naturally (with no medication), you have hypothyroidism).
The good news is that both conditions are treatable and shouldn't interfere with your life very much once you get the right medication dosage. It's not a daily condition you have to manage like diabetes or something. You take a pill and go live your life. Plus, you're going to feel 1000% better, too. You probably don't even realize how bad you've been feeling until you feel better.
As for your other question, no hypothyroidism isn't curable, just treatable. Hyperthyroidism is "curable" in a sense, either with radioactive iodine or with surgery, but most of the time, it is too effective and the person is left hypo-thyroid, which is preferable, but still not really a "cure," if you ask me, more of a trade. But again, don't get caught up in the fact that it's "incurable" because the condition isn't that bad. It's just a pill every day. You can handle this.
Also, please don't feel embarrassed or guilty about masturbation. It's natural, it reduces stress, and it's sex with someone you love. Nothing wrong with that. It's not going to cause any future problems when you get into a relationship. In fact, it will probably be beneficial because you'll know more about your body and be more comfortable with intimacy.
As for what Healthyway said, I think eating right is always good advice for anyone, as well as drinking responsibly and in moderation, but abstaining altogether isn't necessary unless you are taking a medication that specifically interacts with alcohol or if you are having problems with it.
The main things I would say you should do to keep your thyroid under control is to make sure you are taking your medication properly. Take it at the same time every day, on an empty stomach (not eating for an hour after), and not taking calcium and iron supplements within 4 hours. All that can change the amount of hormone that is absorbed. The thyroid hormone pills are very very small dosages (micrograms, not milligrams), so small changes can make a difference. Consistency is key. Also, keep up with your doctor appointments and blood tests to make sure your dosage is right.
If you have more questions, we're here to help. And don't be afraid to ask your doctor lots of questions. Write down a list before you go to your appointment and make sure they are answered. Also, if you are hypothyroid, ask your doctor about being tested for Hashimoto's thyroiditis. It's an autoimmune disease that causes many cases of hypothyroidism and if that is what has caused your condition, there are a few other things you should be aware of, but nothing to worry about right now.
Anyway, don't be depressed. It's all going to be fine. We're here for you.