It's just not happening!!!!

I really feel like I'm having a similar issue. I started exercising 3-4 times per week, including either jogging/walking 30-50min, bike riding, swimming, or just walking. This was at the beginning of June. Since then, I've also been regularly tracking my calorie intake. I am almost always under my intake (1510), unless I exercise, then I sometimes eat more to compensate. I have some days I go over (net) too, so Idk what is going on. My husband thinks it might be my metabolism has slowed down since I am not working right now, so when I'm not working out, I'm usually pretty stationary (computer, tv, lounging outside).
I don't understand what I'm missing. I drink plenty of water most days. But for someone weight in the 230's, I really feel like I should be losing more weight, more quickly. So far I've lost 6lbs since early June, but then the scale says I've gained back 4. Sigh. This is why I usually give up.
Suggestions? Advice?