For two and a half years I have considered myself a Buddhist and admittedly I have made little progress. At first things went well and everything meant sense but then I ended up ending up going into a group of Buddhism that wasn't really right for me. I ended up out of practice. Now I am hoping to get my spiritual life back on track but with a clean slate. I aim to just go back to the basic, core beliefs and practices that are common to most types of Buddhism for now at least. I am considering just practicing a simple form of Buddhism like Nikaya/Hinayana, as Buddhism was when it first came into existence. I do not hope to get into any one the extraneous, esoteric stuff like how I did before.
If you find the Theravada useful, then that's fine. People get too caught up in sectarian differences and forget that ultimately none of that is real; it's just a question of what practices are emphasized, and not all practices will be of use to everyone.
"Nikaya Buddhism" is effectively synonymous with the Theravada, since they're the only ones who still keep the canon in Pali and call them
Nikayas. Other schools refer to them as
Agamas and passed them down originally in Sanskrit and later in Chinese. The choice of language was one of the ways early Buddhist schools differentiated themselves, and both the Pali and the Sanskrit versions were compiled around the same time. The Pali Canon isn't necessarily any more representative of early Buddhism than any other rescension, contrary to what Theravadins like to claim. And none of those early schools at that time still exist, although modern schools can trace their descent back to them, Theravada included.
The main difference these days is that the Theravada have a closed canon, which means they don't accept any scriptures outside of their current version of the Pali Nikayas, whereas other schools have open canons and consider any text that is written from the standpoint of Awakened mind to have been written by Buddha, since Buddha is not just the one guy named Gautama.
There's often the perception that the Theravada is older, purer, and simpler than other schools, but there are a lot of problems with those assumptions, as well as the whole framing of the issue. The bottom line is that you should find a school whose practices work for you, regardless of whether it's Theravada or another school. The very basic teachings really don't differ from one school to the next: dependent origination, selflessness, the ability to liberate oneself from vexations by training the mind to let go of delusions, etc. Everything else is just methods.
. I think the core messages of Buddhism are extremely enlightening; my life improved significantly after I heard them. In fact, I think a lot of other eastern religions like Shaivism and Taoism have similarly enlightening messages to offer. 
