If you're closing in on 30 and you're still unable to make core decisions that affect your long-term happiness for fear of your parents, your parents failed you. You need to move on and allow them to be unhappy so that you can find yours. They'll come around eventually.

For those surprised by my statement above, and pulling this "tHiS is nOt oUr TrAdItiOn!" card, consider first that I spent 12 years of my life staring at rocks and trees in the Arabian peninsula...
But more importantly, consider these statements from scholars of the past:

فلا يجب على الولد طاعتهما في كل ما يأمران به ولا في كل ما ينهيان عنه باتفاق العلماء
Ibn Daqiq al-Eid and other quote al-Izz Ibn AbdelSalam "It is not obligatory for a child to obey them in everything they order and everything they forbid, by agreement of all scholars."

حيث نشأ أمر الوالد أو نهيه عن مجرد الحمق لم يلتفت إليه.
Ibn Hajr al-Haytami states: When a command or prohibition is made out of sheer stupidity it is not to be considered.

ليس لأحد الابوين أَنْ يُلْزِمَ الْوَلَدَ بنكاح مَنْ لَا يُرِيدُ وانه إذَا امتنع لا يكون عَاقًّا
Ibn Taymiya says: It is not for either of the two parents to oblige their child to marry someone they do not want; and if they refuse they will not be disobedient to their parents.

Ibn Taymiya continues: If it's the case that no one is allowed to force someone to eat something they find distasteful while food they do desire is available, then a fortiori the case with marriage is stronger... (cont.)

(Ibn Taymiya cont.) ... because eating something that you dislike is it temporary displeasure while spouses living together with dislike for long periods, is a long term, inseparable harm.