It's perfect expect for the comma. You can't separate two full sentences with a comma. That's called a run-on sentence. You need a period (.) a semicolon (;) or an em-dash (—). But the meaning is very clear and natural. If you wrote this, I'm very impressed!

For the second half of the sentence, it would sound more natural either: It’s been long since we last spoke I don’t even remember the last time we spoke

Also, in the second part, you could use WENT instead of SPENT and it would be way more natural!)))

The second half: I can't even remember what was the last time that we haven't spoke to each other for this long.