All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Whoever is unable to fast an obligatory fasting because of sickness and is unable to make it up, does not have to observe it. Allaah says (which means): {Allaah burdens not a person beyond his scope.}[2:286]. But he has to pay a compensation for each day. Allaah says (which means): {And upon those who are able [to fast, but with hardship], they have a choice either to fast or feed a poor person [each day].}[2:184]. The compensation (for feeding a person) is 750 grams of food. It is acceptable to give the compensation immediately at the beginning of the month, or at the end of the month, or on the same day one breaks the fast. So if you are unable to fast because of ulcer (in your stomach), and did not fast because of the hardship that you faced due to that, and it was a hardship that you could not bear, then there is no harm on you because of not fasting, Inshaa' Allaah, but you have to pay a compensation as previously mentioned.
However, if you did not fast and considered it as a burden just because you want to eat and not because of a sound religious reason, and you become angry and bored if you do not eat, then it is not permissible for you to break the fast or to hate fasting because it is an act of worship. To hate an act of worship is a sign of hypocrisy. Allaah says regarding hypocrites (which means): {And that they do not spend except while they are unwilling.}[9:54]. Allaah further says (which means): {And when they stand up for the prayer, they stand with laziness.}[4:142]. Moreover, the Prophet said: "The heaviest prayer for the hypocrites is Fajr and 'Ishaa'." So hating acts of worship and considering them a burden, implies a sickness in the heart, therefore one has to be careful about it. Besides, you have to know that smoking is forbidden. A previous Fatwa has been in this regard, so please refer to Fatwa: 81589.
To conclude, it is not permissible for you to break the fast if you are not sick or travelling. Remember the saying of the Prophet : "Whoever fasts one day in the path of Allaah [meaning seeking the pleasure of Allaah], Allaah removes the Hellfire seventy years away from his face." [Al-Bukhari] Besides, the Prophet further said: "There is a gate to Paradise which is called Ar-Rayyaan. On the Day of Judgement, those who fasted will enter through it but nobody else. The door will say: "Where are those who fasted? When the last one has passed through it, it will be locked.'' So fasting is observed as an act of worship, and its reward is great on the Day of Judgement. If a person realizes this meaning, fasting will become more beloved to him than eating and drinking.
Allaah knows best.