Well I can understand your emotions. And its indeed a creditable task on your part to think about the safety of your parents keeping in mind the future perspectives. All I can say is that do not worry so much about it okay. Your character shows that you are a dutiful daughter. So even if you get married after few years remain the same. Let the same ideology of loving your parents stand as an example for others. Trust me its your good behaviour and concern which will make your parents feel more happy, relaxed because you are still the same for them. As far as marriage is concerned, I believe that your future husband and in laws will allow you to spare quality time with your parents as well. Do not over think about it. Its a part of life. You will still love your parents and look after their needs. May be time will be a crucial factor but nevertheless you are independent enough to do the right tasks at the right time.