Grassblades is my baby. I love it so much it's ridiculous. I started crying while working on a scene in the upcoming part 5 because I'm so attached to my characters.
I feel this way about a lot of my other comics, but there are comics I've created - and finished! - that I don't feel any particular attachment to. I still finished them, though, because they were good exercise/were fun to draw/seemed interesting at the time - and because when I sit down to do something, I do it. It's a matter of discipline and dedication, really.
I mean, there are moments when I want to give up on Grassblades, too. It's a huge project, it feels overwhelming sometimes, and when I'm sitting there drawing endless lines of rooftiles or colouing foliage I wonder what on earth I've gotten myself into. Those are the moments when giving up is easy - when it isn't fun, and I just kind of hate working on it - and those are the moments when discipline kicks in and keeps me going. Finishing things is important, and it's impossible to finish things unless you make yourself stick with something.
Making comics isn't going to be 100% awesome 100% of the time. Some bits of it are boring. Sometimes you get stuck. Sometimes you colour an entire page, look at the finished thing, and realise you have to start over from scratch because you picked the wrong shade of green and now the entire page looks terrible.
But you have to, or you're going to be left with half-finished projects and abandoned ideas, and I promise you that's worse.
There's a difference between being able to draw hard things (like architecture or cars or super-complicated perspectives or whatever), and being able to finish a comic, because a comic is a much larger commitment. That hard picture your drawing might take you a couple of hours to get right - a comic can take you weeks or months, or in my case, years to finish. Making comics is like running a marathon.
I recommend you start off doing shorter comics. Like, 10 pages or less. Do a couple of less-than-10-pages oneshots, and finish them. Then start doing comics that are 15 pages, or 20, or 30. Build up slowly, and get used to finishing things. The more stuff you finish, the more stuff you learn about your own process, and you can start figuring out when, where and why you lose motivation - and once you know that, you can start working on a way to get around it.