Eat your heart out
To raise an erection, you will be needing both blood and hormones; both of which need nutrients. Therefore be sure to incorporate plentiful carbohydrates, such as pasta and bread, in your diet, whilst zinc is needed for the production of seminal fluid, sperm and testosterone. Zinc can be found in seafood, peas, beans and liver, but you could just take a supplement.
It is important to avoid fatty foods before sex as high fat levels will lower testosterone levels in the body, making erections and ejaculation difficult. In a general sense, high cholesterol may cause circulation issues in the body, hence erectile dysfunction issues, so look after your diet.
If you are on medication for depression, anxiety or OCD, the treatments can have an effect on your erection. Be sure to consult these issues with your doctor as they can carefully manage how much medication you take to still be able to have a healthy sex life.
Whatever you eat, try to give yourself an hour after eating to then have sex so all the food is properly digested and you don't feel too stuffed.
Come in a certain position
Surprisingly, what sexual positions you take part in will affect erection performance. If you are on top, like missionary style, blood will flow down with gravity to the penis. Being on top will also allow you to control your movements, ensuring that you maintain that all-important erection.
It's a sensitive issue
If you want your sex to be longer, you need to reduce sensitivity around the penis. Use of a condom will naturally help with this, but you may want to sometimes shift focus to other things if you feel like you are losing control a bit. Balance this carefully so you do not lose your erection, but similarly do not overthink it as you will find it will have physical effects.
Exercise your erection
Exercise can be a major boost for blood flow, circulation and erections. Abdominal exercises in particular will help your muscles to hold an erection rather than a belly.
Beyond the physicalities, having a toned body will also be a major confidence booster, meaning that you will feel more comfortable having sex. By increasing your sex drive, you can be guaranteed that the erection will remain for much longer.
Change your life
The final point to make is on lifestyle. Smoking cigarettes can cause poor circulation, meaning that the blood will flow less efficiently to the penis. Drinking alcohol will also inflate the prostate and numb the penis, causing sexual issues. Like all things, alcohol should be drunk in moderation.
By making these small and simple changes, you will hopefully be able to see a major difference to your sex life. If you still encounter problems, do not be embarrassed, seek advice from a doctor or sexual health advisor.