The search ads on Etsy don't usually work. Neither do the showcase ads.
Search ads can work with the use of highly targeted keyword phrases.
One of the most effective ways to make sales on Etsy, is to advertize on blogs or web sites that cater to your target market. In your case, I would search for "interior design blogs" on Google and see who accepts advertising and has a lot of search engine traffic.
It has become critical to SEO for both Etsy Relevancy and for Google to get more views.
Add SEO to every part of your shop so that your shop and listings can be found on Etsy's Relevancy search and on Google.
Don't guess on the wording for keyword phrases. Start with using keyword phrases that are often used on Google to search for similar products. The keyword phrases popular on Google are also popular on Etsy.
I suggest using Google's keyword research tool to find appropriate keyword phrases for your listings; adwords.google.com/select/KeywordToolExternal?forceLegacy=true
SEO for Google is more than adding keyword phrases but this is the place to start.
