We should always strive to show our mother and father the most respect possible and heed to their opinions as much as we can. Although your parents cannot designate something halal as haram for you, you must be careful to avoid displeasing them or saddening them. Remember that their behavior comes from a place of deep love and they really do want the best for you. They may be acting in this way as they genuinely fear your choice would harm you and your future. Try your best to work and talk to you parents. Perhaps there is a middle ground? Perhaps there is something that you don’t know about your choice that they know, and vis versa. Ultimately, while your parents may never approve of your selection, you must strive to maintain an excellent relationship and no hard feelings as your first priority, regardless of the decision you make.