yes..that sounds good
but, I think that you turn the words around..
"Tyvärr så var det inte möjligt för mig att vara med på"...maybe it doesn't matter, the word order in English...the meaning is the same, anyway.
I know, but that´s because English and Swedish do not build up their sentences in the same way and with the same word order.
The original meaning has to be respected but the word order doesn´t because it is (in my opinion) more important to write the sentence in an "English-sounding" way than to respect the Swedish word order.
What do you think?