Despite what they tell you in school, LMPs don't make "a great living". However, if you are willing to bill insurance or find yourself in a niche where you get plenty of returning cash-paying customers, you can certainly make do.
The practitioners I know do 12-24 sessions per week. Insurance pays an average of $65 each. In a large city, cash clients will pay around $60, though smaller towns are closer to $35. An employee LMP can expect to earn $20 to $35 per session. Most people simply can't do more than 5 a day over the course of a week, but there are rare folks who can and make a good deal.
I wouldn't suggest specializing in sports unless you are planning on getting an office near a major athletic facility or college. Lymphatic drainage, MFR, or reiki might be equally good choices depending on your personal style and the general culture of the city you live in.
The majority of LMPs don't go on to do massage. Many just do something else entirely while some use their experience to pivot into a related field. I know LMPs who are now currently or getting into medical billing, acupuncture, nursing, physical therapy, and other similar fields.
Keep up hope but make sure you look out for yourself. Don't wear yourself out and you can make a good career out of massage.
One final tip: Auto accident insurance claims are *always* a gamble. *If* they pay, they pay big. However, they often take months or even years before the claims are settled. Sometimes the client doesn't win their claim and you are stuck trying to bill the customer cash rate. In the long run, auto claims are a net positive, but you've been warned.