I have problems achieving and maintaining an erection. what should i do? do i have ed?

It's possible : You're a bit young for ed. Make sure you exercise regularly and drink plenty of water (8-10 glasses a day). If you're heavy, weight loss improves sexual function in most. Also if you drink alcohol, i suggest you stop drinking since it negatively affects sex. If you've done all and no improvement see a doctor for evaluation and hormone testing.