YANBU. (See below for statistics on falling pregnant - no wonder you feel unlucky).
And since you are now onto cycle 16 ttc, and upset, I suggest you start getting some tests done asap if you haven't already.
Some countries make you wait two years, before the public purse will pay. In other countries, tests are paid for after one year. You can pay for your own tests at any time. You might be able to show that you were having regular unprotected sex before you “tried to conceive”, so maybe you are already up to 2 years?
Tests can take a surprisingly long time. Don’t wait until you are absolutely exhausted with ttc. Some tests have to be timed according to your cycles. And 25% of people with infertility end up with no explanation after a long list of tests. Successful medical treatment for infertility (after all the tests) can take years, and will definitely take multiple months. Even referral and commencement takes awhile and generally people will start with low intervention assistance (eg artificial insemination, drugs to ripen one egg), which is less hard on your body and cheaper, but unfortunately has relatively low added value. Eventually people move onto IVF which has a higher chance of success (but still not great with any single cycle).
So unless you actively want to keep ttc just as you are (or you can’t afford to go private), then I suggest you start with the tests. Don't forget to get your partner tested too.
You can continue ttc while you are having the tests done. Don't forget that regular sex means every 2-3 days (which can seem like a lot; not just regular).
Depending on your age, the vast majority of couples will be pregnant after the amount of time you have been trying. That’s why you feel like everyone around you is falling pregnant – if they’re trying, they are falling pregnant!
The NHS reports that among couples having regular unprotected sex:
• aged 19 to 26 – 92% will conceive after 1 year and 98% after 2 years
• aged 35 to 39 – 82% will conceive after 1 year and 90% after 2 years