Well it's taken me over two years thanks to a combination of injury, lack of motivation/depression, new job, family needs etc. but finally I've completed the C25K program. I'm not up to 5K in the 30 mins but I don't let that bother me anymore. I've found real pleasure in the feeling I get after a run, even in these cold and frosty mornings so I'm going to keep it going and may even try a Parkrun soon.
The posts on here have been really inspirational when I've been at a low point, so if you're struggling, let me say "that's OK" and don't give yourself unachievable targets, look at how much more you're doing than a week or a month ago, keep smiling and get there one step at a time. It's great when you do.