You are to be congratulated on your weight loss!
Your strength and stamina are obvious!
Martial arts are hard to do when overweight, however. I found that when I got over 160, I couldn't take the falls in Aikido, for example. I would get hurt, even though I was quite strong and fit at the time. This may not be your experience--and I don't want to discourage you. However, I would use wanting to do martial arts as an incentive at this point! And, in the meantime, I'd work on improving my strength and endurance with walking, treadmill and other exercise machines, weight training, and so on. Try some Zumba or other aerobics classes. There is a lot you can do now!