In this day and age, becoming a travel photographer is not really as hyped a profession as it used to be. People have readily accessible images all over the internet and staying relevant has become a difficult task. Simply put, in this industry, you need to have a notable brand and/or name.
At the end of the day, having a recognized brand is nothing if it does not show in your work. You need to have a passion for both travel and photography to keep yourself relevant. Each day, you should strive to get a single perfect image, and not the thousands that most others tend to look for. Seeing as breaking even is not going to be an easy task, your passion could keep you both sane and alive even as you build a name for yourself.
It is not a professional business, if you keep the photos to yourself. At the same time, it will never be successful if you focus on a single avenue. You could work for newspapers and magazines, have social media accounts and leverage your followers for marketing purposes, maintain blogs, and sell your photos to other companies, among other avenues. The more the exposure that your photos get, the higher your chances of becoming and staying relevant.
Traveling is expensive and photography, especially before you make a notable brand for yourself, might not be sufficient to cover the expense. To avoid drying out before you even begin, it is important that you have a different revenue stream. For instance, I provide online IT services which in turn gives me enough income to maintain my pursuit of travel and photography.
Focusing on a single niche is not so much as limiting yourself as it is seeking perfection in a single domain. Instead of focusing your travel photography on everything, you could focus on a single niche and make sure that you take complete dominance on it. For instance, accommodation, food, and exotic destinations, among others. The smaller your field of focus, the more chances you have of exposure and becoming relevant. While monetizing travel and photography should be something you seek, it should not be your sole focus. Just enjoy yourself as much as possible and everything else will fall into place.