The ultimate decision and choice is yours but here is my take on it. First a disclaimer, I own a Nikon system but I keep an eye on advancements in photography toys.
Mirrorless is not in infancy and has entered its adolescent, now there is quite decent choice of cameras that can rival DSLR in most aspects, the advantage is they are smaller and lighter. If you are not into action photography where speed of focus is of prime importance there is little to choose between the two performance and quality of pictures wise.
How serious you are about photography, because apart from camera a big question is choice of lenses available, DSLR systems are mature and have plenty of lenses to choose from for all kinds of tastes but mirror less has a lot to catch up.
All electronic toys have a relatively short life in today's fast life. A camera you buy today will be probably far behind in technology after five years, this is more true for mirror less because it is in its developing phase.
Photography is not just cameras you own. It is skill and art and a lot is done after capturing a shot.
Do not deliberate too much in any decision making in life it adds confusion in your mind and leads to wrong decisions. Second and third thoughts are fine, rest is a mess.
In my opinion if you are not already an accomplished photographer whatever you buy is not going to make any difference to photographs you take, just get it and go wild with shooting, it will definitely improve your skills.
Whatever you buy don't look around or back enjoy it don't fall prey to buyer's remorse, we already own too much and little appreciate it.
Regards, good luck with your purchase and happy shooting.