I've gone through a similar thing recently. I too am new to the game. Had the usual ups and downs for the first 8-9 months that I played, then last summer started getting far more consistent. Not a world beater, but I won 11 straight weeks in my league, and over half of them were against people better than me. Also won a couple of our in-house tournaments. It was coming together, given the length of time I had in the game to that point.
Then it went all to hell. It's been 3 months of trying to sort out exactly what I was doing differently. Not playing completely awful, but just not very well, certainly not to the level I had been at before.
I think I'm starting to "come out of it" now. Turns out is wasn't any one thing, but a number of little differences in several areas. What I've done to help with this, and hopefully reinforce it a bit, is to write down a short-ish list of the things that tend to get out-of-whack for my particular game. I'm trying to take a quick glance at my list before playing, so I "remember what to remember" that is specific to me.
Simple stuff, really. The usual concepts.
"Stay down, keep the cue-butt down."
"Follow through"
"Minimize practice shots, and do them slowly." (This was a BIG bugaboo for me, it turns out. Many of the players that I play with have a routine of several practice strokes, and making them rather quickly. Sub-conciously I began to adopt that practice, and when I figured out that wasn't helping me, my ball-pocketing went up immediately. Might not be the same for the next guy, but this one makes a big difference to me. Thus my point about the list being specific to "my game". Everybody is different, so there can't be a cookie-cutter list that will help everybody.)
I have another three or four more points to remind myself about. Just basics, and I don't go studying it all night. Just something to help me "find myself" every so often. So far, just once a night as I screw the cue together is how I'm trying to make it work. Hopefully I won't need it at all in the future, and I can safely stash it in the back pocket of the cue-case.
I know I saw someone here at AZB talk about such a list about a year ago, and never did anything about it. Now I'm wishing I did. I realize such a practice will seem silly to the advanced player, one who has many years of experience, and knows the feel of his stroke like the back of the proverbial hand. I'm not that person yet, so these reminders are helping me stay the course. Maybe it'll help our OP, too...?