I am 19 years old and am having serious sexual issues. I have a hard time getting an erection during intercouse and when I do, I almost never can maintain the erection for longer than 3-5 minutes; and I do not reach the point of orgasm through vaginal stimulation. My partner does participate in oral activities and I enjoy it, but some of the time I can't even get an erection through oral. I can however get an erection and reach orgasm through masturbation. I have been dealing with this problem since I lost my virginity at age 15. I have been taking various anti-depressants since 16, and have taken 'vacation weeks' from them numerous times to see if this problem stems from me taking medication.
Although dangerous and irresponsible, I have tried to self medicate myself with Viagra that was provided to me by a friend, and it worked. I was able to get and maintain an erection throughout intercourse, but was not able to reach orgasm.
First, I suggest you to avoid medicine concerning boosting sexual ability. Especially, you're still young.
Exchange them with fruit, especialy apples. It contains abundant anti-oxidan which is good in neutralizing toxin in blood.
Second is milk, choose the low-calorie, like Bear Brand milk. Or directly from dairy-distilled milk, is better. Milk also neutralizes toxin in your body.
Avoid over-consuming fat, fried/junk food, salty!, MSG, beans, and alcohol.
Have vegetable in each meal. The cholofil imbued your cellwound rapidly.
Now te exercise, I suggest swimming. Because swimming makes the whole bodywork. Which part of your body does not mobilized in swimming? None.
When your blood is always in 'fresh' condition. It's more easier for your brain to face distress. The fit condition is also allowing your blood pumps well into penis veins. Those activities will prevent you from the mind of 'wanting sex' or masturbation frequently.
If sex is actively done, it becomes a boring routinity. Then it defects your mind to have a hard erection.
Hope this helps, and good luck in your healthy sexual life.
Besides depression, could you have any psychological issues interfering with sex? Especially for younger people psychological problems are the most common issues.
Could the cause of your depression be high calcium maybe? I had mild depression & anxiety from high calcium intake for years (plus episodes of acute depression from taking melatonin--of all things). Antidepressants only helped me a little bit. I tried a lot of them. Eventually I learned that just limiting calcium intake will cure depression that's caused by high calcium. (If it's calcium-related, phosphates/phosphoric acid also make it worse.)
(Thyroid dysfunction is another very common cause of depression that's better treated with something other than antidepressants. There are many things like this that psychiatrists don't look for.)
Antidepressants often cause low libido, impotence and orgasm difficulty. If you are not seriously depressed, I would try eating better (more vegetables), plenty of exercise, and getting lots of sunlight--especially in the morning. These things help depression too. It takes weeks (up to a number of months) after you stop taking antidepressants for normal sexual function to return--especially orgasms.
Also, it's actually common for circumcised men to be unable to orgasm from oral sex (around half cannot is what people usually say in the US). So I wouldn't worry about that particular aspect of dysfunction. A lot of men are in the same boat.
If you think it's an issue of low penis sensitivity (if you're circumcised--or if you have a natural foreskin too short to cover the glans), there are things you can do to increase sensitivity. The simplest is just don't masturbate, because the more nerve signaling to the brain from the genital nerves, the less intense they feel. Another option is a soft fabric pouch called a foreskin substitute. There's also the option of stretching out a new foreskin (or making an innately short foreskin long enough to protect the glans). This is essentially the nuclear option for increasing the sensitivity of your penis. You need to read more about it before trying anything, and you have to go really slowly and gently or the skin will just tear or be numb. It can take years depending on what you've got to start from, but it is the most you can do to increase penis sensitivity (if you think that could help you). Obviously, it's a big decision and not for everybody. I'm certainly not suggesting you do it; I'm just letting you know it's an option that exists for increasing penile sensitivity.