I worked all day so I just stayed in and watched TV.
I had worked all day so I just stayed in and watched TV.
I had been working all day so I just stayed in and watched TV.
All three sentences are grammatical. There is no ogligation to indicate the sequence of events, particularly in cases where the context already makes that sequence obvious. Nor is there an obligation to use the past perfect when you choose to indicate sequence: "I took a nap after I got home" is grammatical.
The past perfect is a grammatical tool that permits easy indication of sequence in the past, particularly in extended exposition. It also permits a stress on sequence. So, although all three of the sentences at the top of this answer are grammatical, I prefer the second and third over the first because the use of the past perfect emphasizes the sequence: work in day,then lazed at night. Similarly, I prefer the third over the second sentence because the use of the continuous past perfect emphasizes the duration of a full day's work.
Finally, you ask about "I was working all day so I just stayed in and watched TV." That is certainly grammatical, but, for reasons that I cannot quite articulate, it strikes me as very unnatural in context. I would be very unlikely to say it, let alone write it, in the situation hypothesized. Others may disagree, particularly because I am unable to identify exactly what bothers me about the fourth variant.