Can a competitor actually hurt my ranking ( website & store on amazon *etsy ) using junk traffic

Can a competitor actually hurt my ranking ( website & store on amazon *etsy ) using junk traffic or what are the possible ways that they can use and how can Protect my self? if anyone have an idea I would be much grateful

Nowadays, it's a lot more difficult to do so than it was a couple of years ago. Theoretically speaking, junk links or traffic are disregarded by Google instead of outright harming the site but whether this is truly accurate or not is anybody's guess. You can certainly still have your site reported by your competitors for sleazy backlinking practices. I have a feeling this negative SEO method will rise in popularity now that the new update made it so easy to report sketchy activity of a site to Google.

Yeah Cause first they were hitting me with fake IP claims and each time I restored my listings however lately my ads cost have just risen and my conversion rates are down to earth while those suspected accounts still have my images and sell my products , and I just have a feeling they are using those shady tactics now instead of of being more direct as the first times

This could go either way
It's okay to claim that Google can filter such traffic sources
But that's not always the case

As for Amazon, by pouring inappropriate traffic on the listing, you can get the effect only for a few days, after a few days the listing returns to its previous positions. Amazon has long learned to filter unwanted traffic, and this is unlikely to greatly harm the listing. Complaints work much more effectively, as well as ransoms followed by leaving a negative review. There are also ways to steal a listing, change the brand on your listing, photos, etc.
With Etsy, the situation is quite different. Sometimes, pouring untargeted traffic into a listing can even have a positive effect, or no effect at all. Listing complaints are much more efficient on Etsy.
As for protection:
Selling on Amazon You need to have a registered brand and trademark. On Amazon, you need to have a Brand Registry. This way you can protect your listing from hijackers.
On Etsy, things are much more complicated. Even with a registered brand, they can block the store and then you need to prove to the support service that this brand belongs to you.