"...I'm making a switch from a market research sales career into real estate and I'd really love any advice you have to offer as to how you've been so successful..."
The answer that immediately comes to mind is simple: Just keep pushing forward. I remember the period of time from when I was 18 until I was about 25 that everything seemed so hard. I worked too many hours, and there were many times that I felt like giving up and getting a salary-type job. During those times, I had two silly things I would do to help provide the extra motivation necessary to allow me to push through:
1. I would repeat this mantra in my head, over and over, "I made my first million dollars in real estate." (Crazy, I know.) I don't know exactly what it meant because at the time I was broke and hadn't yet made much money in real estate, but somehow it worked for me.
2. I would visualize myself pushing a train up a hill. Of course the train represented my business endeavours. I would always gauge how tough business was by how heavy that train felt. Doing this gave me comfort because I knew that all of that work would pay off when the train reached the top of the hill and I was able to ride off the momentum for the rest of my life.
Sure enough, after a long while, it started to feel like the incline was getting less steep, and eventually, I had the sense that I was at the top of the hill; now, it seems I am at the stage in my career where my focus is on increasing the momentum of the train. Once you have some momentum at your back business gets much easier!
Real estate sales and business are still very hard. It has also been my experience that everything I attempted to do in business is always 300% harder than I thought it would be when I began.
To sum it all up: work harder than everyone else, don't be afraid to make a lot of mistakes, and be open to learning from every experience you put your back into and every experienced person who shares their own struggles with the weight of success.