First off I would make sure you are using an accurate way to check your website rankings. Just doing a google search will give you false results because your browser will show you sites you have visited in different rankings. I use market samurai to check my ranks.

For the SEO If you are doing it all by hand and by yourself then this may be the problem. It also depends how much competition your keyword has. Maybe the site that is the next rank up is doing more SEO than you are and has more to show than your site does.

You should outsource some SEO work or look into some software to help you build more links. Fiverr is great website to get lots of backlinks for only 5 bucks. Maybe have a couple different people do SEO for you on a weekly basis.

Keep adding content and if your seo efforts aren't working then increase your efforts to out do your competition.

I think you should give time to it and leave it for 2-5 days.let it stable and then you can come to the conclusion of its exact rank.

I think its more depend on the intensity of competition, the keyword you are talking about facing intensive competition. You needed to more efforts than usual and try to do more quality work like get more quality basklinks for better ranking

could you mention the keywords that you are focusing for those.

I think this is a good time to see this article for you to have a good idea on how you will get on top of search engines.

Ten Tips to the Top of the Search Engines - Jill Whalen

The keyword is Accredited Online Colleges..

Are you sure, you have unique and quality content on your website? How often you update your website content ??

Well, first of all you should share you website url, check your website content and pLEase don't do junk submissions like directory,article, blog comments etc

try to catch some visitors from social channels too, it will increase some truest on Google eye

Now SEO has become full time job competition is going on so you can say that your keywords will remain at top position ever

[DELETED]

As now after the panda update, google provide social media results more in the results it provided. So you should try to promote your content on social media. May be you have quality content on your site but it be unreachable by people due to mislead title. So social media is better place to promote your content and to get results through it. And then check ranking for your keyword, you will definitely get better results than before.

use different methods clearly the one you are using doesnt work that well! When i do backlinking i try to diversify my backlink strategies!

It means you need to make more quality backlinks because if you have well ON page optimize website and also have unique and fresh content on it then you are lacking in link building only.So keep focus on link building and build more quality backlinks.You can analyze competitor backlinks as from where they are getting backlinks.
Thanks

[DELETED]

Are you using your homepage for seo for all kwds?

If all, that's wrong approach. Always use inner pages for new kwds, especially if your site is 4 years old and has some kwds already high ranked.

This problem is caused due to the change of keyword of your site.It seems like your keyword is quite competitive so such kind of up-down occurs.You need to work hard for that keyword.