How long has your website been up?
How many pages comprise your website?
What kind of keywords does your website target?
How competitive are those keywords?
What kind of content are you using to target your keywords?
What is the search intent behind the keywords?
Do they line up with the intent behind your website?
There's so many questions that come to mind.
You need to provide more details.
Just because your site has been up for four months doesn't really say much.
Depending on the keywords you are targeting, four months may be long enough, or you may have to wait several more months or even more than a year.
You need to provide more info and context so members of this community could help you.