Looking at the pictures you've posted in the thread, it is true that you don't look like a stereotypical runner... but you could. Obtaining a runner's physique takes a combination of factors (good diet, good metabolism, exercise, adequate sleep, genetics), but many of those can be struck out with enough effort on your part to make it happen. Just remember that it will take effort, which is the key factor in all of it if you do want to become leaner and more how you want to look (this means grocery list making, grocery shopping, meal planning, cooking, etc etc).
Your diet should be the first thing you look to when you're looking at where you're going wrong. Most of your 'cuts' and your 'gains' will happen in the kitchen, since caloric intake and essential vitamins/nutrients are incredibly key to building muscle and burning fat. You did say that you're constantly on the move and doing a lot of physically-intensive activities but you're still hungry all the time, so you should be building up your diet to support all that physical activity you end up doing. Are you getting enough protein from your diet to support your muscles? Are you taking in the right amount and kind of calories to give you energy throughout the day? How many carbs are you eating during the day, and are you eating too many?
As a primary suggestion for some reading material (as you said you have absolutely no clue on dieting), I'd like to point out /r/Fitness for their dieting FAQ, as it has quite a lot of information on the subject (with several sources for support and backing). It also links to some different dieting subreddits as well, if you want to venture into those and look at what they have to say as well.
On a side note (but still related), I thought I'd just mouth off what I've found out on my own while dieting and trying to lose weight while keeping my energy levels up:
For the love of all that's good in the world, make sure you're hydrating enough... and make sure you gulp down some before you eat. Carrying a water bottle with you when you go out anywhere (to work, to anywhere) would be a great solution to this. Dehydration and thirst can sometimes be mistaken for hunger or tiredness... and that is something you should avoid.
Proteins, like I said, are incredibly important in any diet - especially for active people, who will need more than those who don't do much physical activity (and I would even say they're more important than the veggies or other foods). Eating meat after working your body and its muscles out will alleviate quite a bit of the soreness you might be feeling after a day of hustle and bustle, and it helps to maintain them (or even build them, if you're looking to also bulk up a little). It really doesn't matter too much if you get lean or regular meat, so long as you're not forking giant pieces of pure fat into your mouth.
These are lower-calorie, delicious-and-nutritious filler foods that will help to take up room in your stomach without easily making you go over your caloric limit (mainly thanks to their high water contents). You'll get a ton of vitamins and minerals from the two groups, but you'll want to do research on your own if you want to know which ones give what vitamins.
I know some diets emphasize low carbs - and while I do think that limiting your carb intake is a great way to lose weight, it might not be the best way for an active lady that's looking to do something about her energy problems after exerting herself. Carbs will give you longer-lasting energy to do the things that you do, hence why many cyclists will eat a large, carb-filled meal right before cycling marathons. Also, I know oatmeal is highly-regarded in the lifting community as a low-calorie energy staple, and if it works for them it's definitely something to look into.
Just keep in mind, in all of this, that calories really do make the difference in everything. As an active woman from the ages of 18 to 30, you should be taking in roughly ~2400 calories to maintain your figure, and if you're looking to put yourself at a good deficit I'd say 2000 or 2100 would be a good number to see some results happen in a timely but gradual fashion. As for counting the calories in your food right now I see someone's already suggested MyFitnessPal, which is a great way to keep track of that.