Is there a toothpaste or any thing can make our teeth protective surface stronger, since in past i had to eat lemons and brush my teeth directly after?

Yes: Fluoride toothpastes and remineralizing pastes. I'm not sure what is available in your area. However, not that nothing can counter poor oral hygiene and poor diet, as well as foods and liquids high in sugars and acids.

Sensodyne toothpaste: There are many causes for sensitive teeth like tooth decay, brushing too hard, receding gums, gingivitis and grinding or clenching your teeth, acid erosion (e.g. lemon, soda) could also be one of the causes. Sensodyne toothpaste for sensitive teeth that will protect your teeth, keep them healthy and strong. ask your dentist for more information. Disclaimer: no personal interest in this CO.