What is a good way to keep you motivated to stick to eating healthly?!

You need to have a fat bank balance.Now because there is more awareness about healthy eating merchants and enterpreneers are profiting from this trend.The healthier foods are now sold in a special health food store and are more expensive than ordinary foods you buy in a supermarket.
However fresh fruits prices are not so bad yet.You could substitute your sweet and choc habit with some sweet tasting fruit and also eat more salads.Since you like the taste of sweet things try cooking your foods with a sweetish flavour.,make a sweet-sauce?Sweet salad dressing on your salad.For example try a Chinese sweet n sour recipe......

You answer your own questions.
You say you want to be healthy and strong but you also say you cannot help but eat junk at least once a day. Chocolate, cookies or biscuits are not going to make you beautiful or strong but they will make you fat and ugly.
Grow up and exercise some will power. You have control over what you put in your mouth... use it!

chocolate is healthy..so try to make another version
like make cocoa milk, by adding to hot milk cocoa powder(not the low fat one, the less it was messed with the better), a Cinnamon stick and honey to taste..cover it up and let it sit for maybe 15minsto half an hour, this way the ingredients taste will absorb into each other
make ur own healthy cookies
http://allrecipes.com//Recipe/whole-whit…
so don't cut back just make ur own food, so u chose what u put in..and whole flour is healthy and this recipe has lil sugar content
so u cook according to ur ingredients and try to use whole foods, and u can change a recipe as u wish..and maybe look at the comments, they sometimes give u good cooking tips

also a healthy alternative to chocolate is stuff made with carob, just sue less then u would use with cocoa or chocolate

Just cut down on not eating to much chocolate by not letting yourself be tempted to having that hungry craving but switch to a healthier snack like Nature Valley granola bars.

Keep a food journal. Write down everything you out in your mouth. Use it to to make sensible choices.

If you have healthy meals and don't skip meals you shouldn't be wanting too much junk. That's what works for me anyway.

I grew up just like you. I was an overweight teenager and when I got to college, it only got worse. Then I faced a series of intense brain surgeries and that made an excuse for me to not to have to exercise, so I ballooned up even more. Now , I have hit my peak weight and let me tell you, when I saw the scales at the end of January, I cried. Literally. I took matters into my own hands. No fancy diets, no gm, special pills.
I learned some tricks.
At the grocery store, the 'real ' foods are around the outside edges of the store- the dairy, the meats, the veggies. Stick to the outside. THE over processed, sugary stuff is in the middle. Stay out of the bakery, except for the multi grain breads, and eat those sparingly.
To stay motivated? Get a buddy. I have a friend and we keep each other motivated, alot. We have increased our water intake, and lowered our soda intake to almost nothing. She has switched to diet sodas, but I am allergic to nutrasweet and splenda, so that is kind of out for me, but that is OK. I would rather have juice or teas if I'm going to have something besides water.

I have also seriously, SERIOUSLY increased my activity . I have been , of all things, cleaning my house! I mean... c-l-e-a-n-i-n-g my house. Boxes and boxes of JUNK have been going OUT THE DOOR for a garage sale. My house has been neglected for a few years because of taking care of my health issues and a seriously ill husband ( 68 brain surgeries between us... we've had other things on our mind.. no pun intended.. LOL ) and so my house has now gone from , huh.. Rosanne Conner to Martha Stewart as part of my Work Out plan!and its working!! Dusting shelves, moving boxes, walking all thru the house moving things instead of mkaing piles to move, later... even if it is taking a stray piece of dishware to the kitchen.. I"M MOVING.
So start moving- start walking, riding a bike even if you have to borrow one, see if you can start swimming somewhere, anything to get MOVING..it makes all the difference in the world.

AND WHO CARES ABOUT BEING GORGEOUS?!!? Wouldn't you rather be healthy and happy with who you ARE??? Let me tell you.... At your 20 year high school reunion, you'll loook at all the girls who used to tan and get all golden brown and they'll be all wrinkled and look like dried leather and you'll be able to snicker in your head at them! Some of the blondes will be desperately trying to hide their gray hair with the worst blonde dye jobs you've ever seen and will look like q-tips instead...laugh at them in your head too.. but you'll have an amazing, fit toned body, and they'll be like " DANG...she got it together! Look at her..is that really HER?!?! Boy, her hubby is cuuuuuuuute, toooo.. bet their kids are adorable!!" And it all starts now, sweetie. Thing of THAT as your inspiration. Hey, think of PROM as your inspiration... use THAT prom dress as your inspiration NOW.... That is an even more immediate goal, huh?? So lay those cookies aside... there are some awesome yogurt flavors...and fruit is fantastic for your skin as well...

I wish you well and I hope I have encouraged you. If I can do it, and it is much harder AFTER 40, like me, then I know you can!