To hire a SEO firm?

I have been doing a little SEO to help my site get some traffic but still no improvement for almost 6 mos now. So I am thinking whether to start looking for a SEO company or try out some other ways to boost my site's traffic. This is not really easy especially if your knowledge is not enough. If I will be hiring a firm to do the job for me, it might be a bit costly and that's my problem too. lol. So what are the other options can you suggest? Or do you think it's time for me to get a professional one? o_O Thanks.
Hi, Sinip! I'm continuously updating my content and reaching out to different websites for possible guest posting plus, I keep my social media channels busy all the time but still no improvement. I tried to search for some possible reasons and found out that having broken links may affect the site. This can be possible I think as I am not checking them regularly. What about the meta tags? Coz I also read that "Meta tags, including title, description and keyword tags, summarize the content on your site. However, if the tags don’t match with the site niche or the content, placement in search engine results will suffer." (source: Is this correct? I'm getting tired of checking all by myself. Perhaps hiring an SEO service can help me resolve my site's issues.