Overcoming drowing fear

Hi all. I love the water in fact I work in aquatic sciences for a living and am dive certified though I haven't been diving in years. About 7 years ago when floating a river I almost drowed. I was going off course in the float and slipped out to pull it and swim myself to shore and as it was happening I just panicked. Not sure why I just did. Luckily some folks camping came and scooped me out. After that I felt so ashamed because this was literally my job to be in the water and I'm over here drowning. I took a couple swim lessons to ease myself back into it and learn how to avoid panic (I have never been a super strong swimmer anyways but always made do). Now I'm just so ashamed and still have some residual fear. Any tips on conquering this.