How we cite our quotes:
Wishing me [...]
like him with friends possessed, (5-6)
This is where our speaker claims that he doesn't have any friends. We're starting to understand why he feels so lonely.
With what I most enjoy contented least; (8)
When we hear that the speaker doesn't find any joy or pleasure in the things/people he used to enjoy the most, we wonder just how much of the speaker's isolation from the world is self-imposed. In other words, is he really an outcast, or is he just feeling sorry for himself?
Yet in these thoughts myself almost despising,
Haply I think on thee, and then my state,
Like to the lark at break of day arising
From sullen earth, sings hymns at heaven's gate; (9-11)
Wait a minute, folks! It turns out that our speaker does have someone special in his life: "thee." Not only that, but just thinking about "thee" is enough to put him in a better mood and make him feel like a bird that rises up and "sings hymns at heaven's gate." That's a huge step. Earlier in the sonnet, our speaker said "heav'n" was ignoring his cries and prayers (3). But now, it seems like heaven might be listening to our guy. Does this mean he no longer feels isolated from God?