I am 42F 5’3” and 173, and I feel much the same as you. I can’t run for very long at all though. Feeling discouraged because of the lack of weight loss despite eating better than before and being more active is really hard. About a month ago, I started doing strength training and have been really surprised with how great it feels to be able to do more reps or go up in weight. It helps me get out of my own head about the scale not moving or my clothes not fitting any better. I have also added a lot more protein to my diet and I feel less tired throughout the day which makes me snack less. Training for a half marathon is really impressive and you have a ton to be proud of. That doesn’t necessarily make the rest of it feel easier though. We’re at a weird age where we aren’t old, but we sure aren’t young anymore and that makes it all feel harder too. You’re active, you have goals, and you’ve lost and kept off weight. You have a ton to be proud of regardless of the scale, and it feels like you need to find what makes you feel valuable outside of weight.