Hello.
The first thing you can do is reduce the anxiety related to premature ejaculation. You have to know that this condition is not very uncommon and happens with a lot of people. And with persistent efforts and practice, this can be overcome.
Unfortunately there is no quick fix medicine that will improve the condition. However, there are some antidepressants, especially Prozac (Fluoxetine) which can delay ejaculation, as a side effect. You can consider that option.
Apart from the medicine, you can take some measures such as breathing deep and regularly during sexual intercourse, taking a more passive position (lying on back), stop and start technique, squeeze technique, etc. You cac read more about these techniques from Google search.
Hope this helps.
Abhijeet Deshmukh, MD
(This post is for the purpose of providing medical information and is not a substitute for a face-to-face consultation with a doctor. This post is not intended to give or rule out a diagnosis, create a doctor-patient relationship or replace an existing one. I am not able to diagnose medical conditions online. Please consult with your doctor or a qualified healthcare provider for diagnosis and treatment options)