First, you can easily test that thesis by searching incognito, using a VPN etc. Check not only for search ranking but also if you are showing up on other people's listings in your field.
Second, there are sometimes good reasons that traffic can fluctuate, including promotions by Etsy or someone else, a mention of a general product on tv or elsewhere etc.
Third, you have some recent low feedback which may have hurt you in search and other places - that is part of the algorithm.
Fourth, your items show as arriving after Christmas now, so your sales may be more erratic for the next few weeks until we get past the holiday.
Fifth, as mentioned above, a quick search of dinosaurs show that other shops are using the exact same dinos in their designs. That may contribute to buyers thinking you are not the artist, or buyers opting for something similar that is cheaper. Work on expressing why your dinos are better than the other dinos that look the same. For example, is your decal quality better?
Finally, Etsy's algorithm is much more personalized and contextualized now, showing different items at different times, to different devices, to different age groups etc. There may be something abut your listings that Etsy thinks does not appeal to certain groups or situations. There may or may not be a way to alter your offerings to counter that. Back when I was seriously selling here, I didn't have this problem because when my more popular items dropped in sales, my niche items picked up. I had 2 items where Etsy would show one higher on the weekends (the cheaper item), and the other during the week. They were both still visible, but one ranked higher on page one at different times. Having more options made my sales more consistent - now that I have removed most of my items from Etsy, my sales vary more widely.
[I'd strongly recommend asking for a critique. I noticed a few things which could hurt you, such as typos in the panda balloon print]
