Thanks for your query.
Based on your description.It is sure that your husband has a problem of what is called as Erectile Dysfunction
.Since erection is a complex process involving Psychology,nervous and cardiovascular system There are multiple reasons for dysfunction The commonest are
2) Cardiovasclar prblems
3) Side effects of some medicines.
Please get his blood sugar level done to rule out Diabetes.If he is smoker ask him to stop smoking Have a diet rich in protein,Fruits and vegetable.Take some moderate exercises .All these measures will boost up his physique and confidence.He is 35 years old There is no age bar for taking Sildenafil(Viagra
) so he can take Viagra 100 mg 1/2 hr before intercourse.If his problem still persists after trail of Viagra for few days consult some Urologist
or Qualified sexologist
for proper evaluation and further treatment.