because I'm really enjoying the way that cardio makes me feel, and I've been losing weight in combination with healthier eating.

See that? Shes LOSING weight!

Now, if you happen to have an engineering degree like me, you understand that when you push down with a weight of 250lbs, and when you push down with lesser weight, what happens? Thats right, you have to exert yourself MORE, because to create the same amount of downforce with 250 lbs versus a lighter weight means that the force has to INCREASE.

So, as she loses weight, she actually has to work her body harder in order to get the same workout she did when she weighed 250 lbs. When you work your body harder, what happens? Thats right, youre gonna hurt.
Its not irresponsible, its part of basic laws of physics. And if you noticed, what did I advise? BACK OFF, and BUILD UP.