1. I cut my hair during sefira, forgetting that it was sefira. Should I now keep all of the halachos of mourning for sefira during the entire omer until Shavuos?
2. Does it matter if it was done as a part of chafifa before tevila? (I did more than cut length though, I cut for style as well)
What was done was incorrect, however post facto, you do not have to keep the second part of sefira instead. Similar to a person who mistakenly heard music during sefira- he doesn’t have to keep the second half if it isn’t his minhag.