I have always been a single.

[tufguy]

Valentine's day is not for me because nobody likes me and I have always been a single and I am at the present is.

Is it correct to say "I have always been a single"?

Is my last sentence correct " I am at the present is"?

 

[5jj]

No. delete 'a'.
No. It's meaningless.

 

[emsr2d2]

Valentine's Day is not for me because nobody likes me. and I am, and have always been, a single. and I am at the present is.

Is it correct to say "I have always been a single"? No.

Is my last sentence correct - "I am at the present is"? No.

Note my corrections above. You must capitalise "Valentine's Day" because it's the official name of the day. You can't say "a single". "Single" is an adjective, not a noun. The end of your main sentence was, in all honesty, dreadful. I can't imagine what made you think that "is" was even possible there.
I think you were trying to say something like "I have always been single and I'm still single now".

 

[Tdol]

I am single at the moment??

 

[emsr2d2]

"I have always been single" includes the present time so there is, in fact, no need to add anything else. If you weren't single at the time of writing, you'd say "I had [always] been single until a few weeks ago [when I started dating a lovely woman/man]".