35 years is not an age to worry on erections . take up yoga and breathing exercises . eat fruits and vegetables avoid junk food and loose weight
First of all quit smoking and indulge yourself in exercise activity. I used to smoke before and was in similar situation you are in right now. I tried viagra after i stopped smoking and later I stopped using viagra as it made my flush so I switched to cialis
Bgviking is right: a healthy lifestyle can do wonders for your sex life. Lose weight (there are several studies that show that obesity is a major cause of ED), stop smoking, get some exercise. Oral drugs are very effective but they should be taken under the supervision of a doctor. There are only two types of oral drugs that really work: PDE-5 inhibitors (Viagra, Cialis, Levitra) and VIGAMED (oral phentolamine). Everything else (incl. 'herbal' supplements) is useless and a complete waste of money.
Change your lifestyle. Stop smoking, start to exercise, run minimum 60min 5 days a week, and go the gym if possible. This should give you energy and very possibly regain your erection quality. Do it for 2 months and post back on the progress. :) good luck!