Hi
To begin with , I would like to ask you , have you seen a medical specialist for your issues ?
Being stressed and having negative thoughts about satisfying your partner will not be of much help to you. As having negative thoughts will reduce your libido all the more.
Seek opinion from a medical specialist to find out any reasons or any deficiency causing the same.
Also , try managing your stress levels and negative thoughts by maintaining a healthy lifestyle
A healthy diet
Maintain a daily logbook of positive thoughts of the day
Communicate it with your partner and try to mutually work through this.
Seek psychological counseling for further management of your issues.
Next Steps
healthy diet
healthy lifestyle
seek opinion of a medical specialist
seek psychological consultation for stress management and negative thoughts management