It can be difficult, but please don't fall into the trap of thinking that you must eat perfectly on plan and be able to effortlessly run through all your exercises on Day 1, else you're a failure! That is a huge, huge trap and one that causes many chicks to post here for a week or two and then fade away, because they feel like it cannot be done.
It can be done. I'm not at goal yet and I started 16 months ago. I have been maintaining for about 5-6 months despite having more to lose. Do I wish I was doing better? Yeah, I do. But I'm doing OK and right now, that's enough for me. I've still lost 50 pounds and that's light-years better than where I was when I started.
Maybe it will help to start with baby steps. These are the steps I took, for example, and I ramped up over the course of several months. I waited till I got in the groove with one step till I started the next.
1. Stopped eating out at lunch and packed my lunch instead.
2. Stopped buying junk food....no chips, no candy from the machine. No cookies from the grocery store, no tubs of ice cream (I did allow Skinny Cow ice cream). Also started counting (logging) calories at this point.
3. After 5-6 weeks of diet change, I bought an elliptical machine and started using it. I think I was able to go 6 minutes the first night and I thought I was gonna die. But we all have to start someplace, right? I started tracking it on a spreadsheet so I could see my increased progress.
4. When the weather got better (April), I started walking 2 miles a night. Then 3. Then 4.
5. Started Couch to 5K in May or June. It was on again, off again due to asthma. Again, if my asthma was bad, I would load up on inhalers and switch to walking or using the elliptical instead of running.
It's a process, or at least it is for me. There are many chicks here who dive right in to exercise, changing their diet, and all that right off the bat. Many of them do great and I admire them for it, because they're slim and I'm still not!
But what works for me is to make small changes. I didn't feel ready to exercise when I was at my heaviest, but I sure didn't mind substituting a fat, juicy orange for a bag of chips. So that's the way I did it. One step at a time, one change at a time. And guess what...I still can't do a single push-up, so you're already WAY ahead of me there!