If you are that worried about it just call the local county tell them what happened and let them know that you could notpull over due to traffic. Just let them know what happend. If it was reported you will get off easier if not they will probally laugh at you for being so paranoid (I would be too) and let it go. Its better to assume they know and call them then to assume they don't know and hide the fact.
If you are confident that no damage was done and no one was hurt I would not bother calling. If you are uncertain I would call and take responsibility for the scene. Chances are you'll be fine even if it was reported.
To answer your question no you have not commited a felony. Worst you will get is a ticket for littering but under the circumstances I beleive you will be just fine. Sometimes its better to get shit off your chest.