Saying Goodbye to Another Year

As 2018 comes to a swift close, I find myself as reflective as anyone.
I went to Europe for the first time this year. That was a huge event for me. I'm not exactly the most accomplished traveler by any means.
I started a new, fantastical relationship that's been far more amazing in my life than I could have ever imagined.
I finished and published my third novel (and the best I've written so far if I do say so myself...for now).
I moved into my own apartment for the first time in way too long.
Being the self-critical person that I am, however, I always find myself focusing on all the things I'd wished I'd done or would've gotten around to far more easily than I wish I did.
The passage of time is a strange thing for me. I tend to get too hung up on the notion of what could have been, what wasn't, what only I would do if I could now that it's over. I find myself struggling to say goodbye as days, months or years pass from one to the next. With 2018 ending in a matter of hours, that's it! I don't have a say any more. The year is just gone. I can no longer make any changes to it. I can't do any better in 2018 than I've already done once the new year rings itself in. I can't will the countdown to take any longer or the seconds to cease their marching...
And it drives me wild.
I struggle to focus on the good things, allowing myself to get caught up in what I wish I could change now.
If only I'd written more...
If only I'd marketed myself better...
If only I'd saved more money...
If only I'd pushed myself harder at the gym...
If only...
It's not like those thoughts aren't with me throughout the year, but the new year's celebration really brings it all bubbling to the surface. I'm going to be another year older in 2019. I'm going to be another year closer to not being able to accomplish anything anymore. Every period of time that ends is just another nail in the coffin between me and what I'd wished I'd done.
And I'm so tired of feeling that way.