I wish you try to get a copy of 'Karma Yoga' by Swami Vivekananda, a small booklet, but it clears all your doubts. As regards to your wife, never think you are superior to her in any way. Respect her feelings, love her as your own, and fulfill all her wants. In most of the cases, the simple ego is the cause for the quarrels and misunderstandings. This applies to your wife too.
Married life is no bar to practise spiritual life.
Every minute of our life can be spiritual whether we work or pray. Doctor's is a holy profession. You have great opportunity to relieve the sufferings of others. The more you sacrifice your time the more you can serve them. Thanks for the mail.