Absolutely crucial to the successful development of a yoga student is happy marriage. Unhappy marriage will be useful for him or her in terms of providing experience and developing mental strength. However, happy marriage is essential:
You need a stable base of happiness from which to help others on your part of karma yoga
You will not develop full faith in yoga if you are not personally in a happy marriage
Orgasm outside of a religious marriage involves harm to you or your partner, and yet orgasm is needed if you are to have fresh energy circulated to your brain in order that you can help others
Having said all that, nowadays there are almost no successful marriages. There is no possibility in a successful marriage of the breakup, of discord or of argument. Since you and none of the people you know have experienced a successful marriage, you do not believe that it can happen. You become satisfied with the norm, or have decided that marriage is not for you.
Much of my personal advice to students involves helping them in the dating process, finding a suitable match, proceeding carefully to marriage, and structuring a marital agreement such that the marriage will be a success.
A random approach, as almost everybody today adopts, to this most important aspect of your life will not succeed. At the very least, you need to pray to Lord Ganesh for guidance on this topic.