I started in residential rentals- made money my first week. Pretty cool, except the checks weren't very big. The ceiling where I was, in rentals, would be about 50 grand.
I abandoned that, having gained a lot of knowledge and went into commercial sales. I am coming up on my 6th month. It is VERY VERY VERY VERY VERY hard. Very.
I am filled with doubt, pessimism, anger, frustration. But the light is always there. There is a lot of money to be made. Yes, the market is tough. But take a look at the number of closings- they are still happening. This 'bad' market is actually bad for those who over-extended and planned to flip ludicrously over-valued properties (bad for owners who blew it). The savvy salesmen in my office are still making dough. I just need to be savvy too.
Choose your office VERY carefully. Each office you interview with will spew all kinds of stats about why their office is tops. They are SALESMEN, after all. Do your own research, see which offices are listing the most and which are closing the most. This can be quite telling- an office that lists 100 properties and closes 5 is most likely a group of "order takers", where the agents list at whatever price will get them the listing, regardless of if it closes. Not a good business model IMO. Chances are, with a successful career behind you, most offices will readily hire you, so YOU have to be the choosy one.
I have assumed you are going residential- if you are considering commercial, there are other factors to consider too. Maybe I can get you an interview with my company, and then maybe I can get some kind of referral bonus from them hiring you. I'll look into that- if it is true, then your best option is to work for my company.