I want to say something like: from now on I will work on my second task.
Is it correct to use "onward" (just onward) at the beginning of the sentence to replace "from now on"?
Onward, I will work on my second task.
Edit: To give context to this sentence (requested on the comments) - the sentence should express future plans in a sequence of events (which is tasks completions). By future plans I don't set a specific time in the future but wish to imply to the near future - in an hour, by tomorrow etc.
Something like: "I have now completed my first task, and I am about to start my work on the second task."