It seems that men are experiencing at an earlier age problems of "keeping it up". And that more and more men are having these issues. Any number of circumstances can affect this. It can be medical and /or physiological. Or both. Treatment is always the best when earliest diagnosed. Don't put off your health. Visit your family doctor regularly. And most of all- don't be embarrassed, you have to talk about it especially with your doctor, if you don't tell your doctor - how can your doctor help you. The longer you wait, you are putting yourself at risk to maybe not being able to reverse or minimize the effects. And this means also mentally too. If you are already stressed to the point where even thinking of having sex is already unpleasant due to you unable to stop thinking about if you will be able to perform, then maybe it is time to make changes. There are different avenues to take. Note that there is not a cure-all for it, but if you do nothing - nothing will change.
Have a talk with Guru Miss Kitty and start your personal self journey today.