Just my opinions:
You dont mention if your goal is airline, but you are here, so we will start with this presumption.
To get there you will need an absolute minimum of $30k work of training and probably more along the lines of $60k. The FAA minimum for training are nearly impossible at our age. Half way through my instrument training I was getting enraged by kids half my age picking up the processes in half the time I was taking. Their absorption is MUCH faster....our application is much better (eventually). Be patient if you can afford it. But do NOT go in budgeting to finish the process in the minimum time. Budget for it to take double time...if you come out ahead, save it. And, no, I'm not a moron. My wife is a psychologist and I have every "test" known to man. It is well documented that I am significantly ahead of the curve...but simply put, age effects learning. You can
teach an old dog new trick, it just takes longer.
You dont mention if you have family. If you do and your relationship if weak...dont pursue airlines. Family Counseling and divoce are not covered in the benefits program. My folks are dead, my siblings are busy elsewhere, I have no rug rats, and I have the most amazing wife anyone could even imagine...but ist still gonna be a strain...if I get a call.
Most of all....examin your motives. Ask yourself why you want to do it.
Really pull at the answer (dont just tease it with a feather duster) tug on it from all angles. If the answer comes apart....reconsider. If the answer holds together....keep researching....reading threads...network with active 121 pilots....and Keep examining your motives every step of the way. If the answers pull apart....reconsider. If through all of this the answers hold together....then you are on the right path.
I'm not trying to talk you into or out of anything. But plotting a career change at any point requires a lot of navigation. Plotting a chage at 41 with more than half your fuel-burn behind you...requires VERY CAREFUL navigation. But you can still get there.
Be patient. Have fun. but situation awareness is far more than an aviation term, it should be mantra for life.
Again....just my opinion. Welcome to the paradox. PM me if you have questions that my relative inexperience my be able to help with.