Hi Maggie, and first of all: welcome here!
I've had this problem with "bad foods" for a long, long time. I didn't crave vegetables and fruits, but I could go a whole week eating pizza, potatoes, pasta, fast-food, cookies and other junky stuff without even blinking. If this can help, here's my answer to your question:
What caused me to really think about it and make "the" decision was two things, in fact. The first one was reading Phil McGraw's book (The 7 keys to weight loss); it may seem "only a book", but it spoke to me in a way that no friend nor family member had ever done, and helped me think and understand why I had many "bad" food behaviors - as well as giving me ideas about how to correct them. The second reason was health-elated; I got the results from a blood test, and on the last sheet, the lab had indicated in bold letters "significant cholesterol increase since last test" (last test being a little over one year before this). This made me seriously freak out, as even though I wasn't terribly overweight nor out of the norm yet regarding said cholesterol (okay, so in truth, I was just barely under the limit), the fact that in one year it had grown so much made me suddenly realize that it'd only grow worse if I were to go on this way. Here also it may seem a little dumb, uselessly panicky or whatever, but the goal was reached no matter what - it had on me the effect of a slap in the face.
Granted, it's not a fairy tale, and it's not easy everyday. It's been two months now, I still crave fast-food and all the junk I was eating before, and at times, I will still "afford" something I shouldn't (to be more exact, I will afford bretzels - McDo, I can cut on, but bretzels? **** no, my Alsacian blood is speaking too loudly for this!

). But I keep it under strict control and I "work" to convince myself that the good foods are also tasty, which in fact they are. I stopped focusing on "I don't like veggies" to focus in turn on "let's take a few minutes to truly taste this veg/fruit", and it made me discover that in fact, I liked them more than I wanted to admit it. It doesn't work for all, but I tend to appreciate certain fruits etc more now, and to "feel like eating them", which helps in staying committed. I wouldn't say it's a "struggle" for me, it's more like getting slowly accustomed, and once I am, things seem easier and more pleasant.
Exercising is another thing though, although showing up to the gym is, IMHO, half the battle won. But you can also try to find an exercise you like: doing cardio on the bike may not be what you'd find fun after all, perhaps you'd be more at ease at the swimming pool? I personnally like weight-lifting a lot, but cardio bores me to death, so I try to make it funnier by going to classes (like step aerobics) rather than just me and myself alone on a bike. Long walks/hiking can be very nice too, with discovering new landscapes or places you live close of yet never visited before, and so on. It's always better if you can get some kind of "enjoyment reward" out of it.
Finally... you feel better. Truly, you do. Less bloated, less "heavy", more bouncy, more prone to go out, have fun, move, etc. You sleep better, too. This is both the combination of healthy eating and exercising. Every time I'm tempted by fast food junk, I try to focus on the bloaty feeling I have afterward - of being "filled with grease", heavy, not exactly well yet without being able to point out what's wrong... I never have this feeling with healthy food, and thus I wonder: is the trade-off such a good deal? I then realize that it's not, and that feeling good is more important. The few times I've allowed myself to eat at McDonald's, in the past months, I've always felt almost physically ill from it, so it doesn't encourage me; my body doesn't really want the junk anymore, haha.
This is all my personal experience, of course, and it may or may not help - after all, we're all different and don't react to the same cues. But really, it's about deciding what's important: being healthy, being in control of at least one thing in my life (=what I eat), not going on piling the pounds up, etc...
Oh, before I forget - eating healthier doesn't mean constantly depriving yourself of *everything* you like! I follow the Montignac method myself (the Sugar Busters way of eating is quite close to it) and I'm "allowed" to eat pasta and bread (which I love too!), provided of course it's not two meals a day, that it's not refined (pasta without eggs, brown rice, complete bread...), and that I limit bread to breakfast, too. However, it's way easier to think about things this way, rather than mourn over "never any slice of bread again in my life". Deprivation/frustration feelings can really take you down in this, hence why choosing a way of eating that suits you well is important. (Let's not call this "diet"; diet is temporary and its effects don't last once you stop it...)
Anyway - sorry for the little novel of a post. I hope it could answer your question, it's always nice to see what others are doing, how they "react" to their choices, how it works, etc. None of us here is alone in this