Congratulations on losing 40 pounds!
To your first point, it's great to see you say that: I see this repeated so often, yet I observe very few people actually internalizing it even when they hear it from others. The most effective and efficient method for consistently losing weight is diet control.
Exercise (specifically the type and intensity) changes body composition, but diet alone impacts overall mass. You can't expect to lose much weight just because you're running - it might push you into a caloric deficit if you're not already, but it will take focused effort not to unconsciously eat more to compensate if you're not used to controlling your diet already.
Gaining mass at a caloric deficit will be impossible no matter how much weight training you do (but again: composition will alter), and losing mass will be impossible at a caloric surplus no matter how much running you do! Someone with specific fitness goals needs to strategically optimize both their exercise regimen and diet.