Sanity Check - Taking on too much exercise? (adding Martial Arts?)

For those who have been at the exercise thing a while, I need to do a sanity check. Bear with me, I am giving more background that normal so you can assess and advise.

Background:

• 41 Yr Old Father of 3
• 8lbs lost over 6 weeks, at 237lbs
• Calorie intake 1990 base + Exercise Calories (I calculate at 25% less than MFP suggests to eat) and I do eat my exercise calories.

I found going to the gym is tough for me, although I loved it for years. Schedule just doesn't mesh when I am married and have 3 kids. So I started...

• Two weeks of just counting calories
• At 3 weeks I started walking 2 mi 3x a week
• At 4 weeks I started walking 3 mi 2-3 times a week
• Past two weeks I have either walked 3mi or Biked 10mi roughly 4-5x a week. This is my new routine.
• I am active on weekends, but nothing like the routine above - Mowing Lawn, chasing Kids, Projects around house....

I introduced cycling to break the boredom of a 75-90min walk. It kicks my *kitten*, but I enjoy it and its low impact on my knees.

Here is the thing, I'm feeling it. I'm constantly sore. I'm getting too old for this <bleep> but I am determined to stay active at least an hour a day where my heart rate is up. I'm not sure if this is going to be a permanent, "you are getting old, get used to feeling tight and sore all the time". Or if this will pass as my body gets used to it.

The next step in my mind was to introduce some sort of resistance training or strength training - be it rubber bands or weights at home or slapping weights on my ankles when I walk. But then this happened.

Here is the question...

My middle daughter (7yr old) and I visited a local Tae Kwon Do school and she is very about doing it. The school is N I C E and even piqued my interest. They offer parents to come in at like 20% of the cost because they want parent involvement. My daughter is all about this. I would actually go to class with her.

Would I be pushing it too hard if I was doing my normal routine in the morning for 1-1.5 hours an then do Tae Kwan Do for an hour 2-3x a week?

I have no interest in starving my body and I will eat the calories as long as I am at that 1lb a week loss. But I am wondering if I am just beating up my body too much.

Thoughts?