Sounds like you have made the first step yourself and you are on the way, like you say keep the momentum up.
If all else fails, or you feel the need to go to the pool more often that the lessons, get a able swimmer friend to go with you for support and assistance.
If you can get out of work, go during the day, the pools are usually quietest midweek (or strangely enough midday Saturday during term time), ask the local pool when they are quiet. Go then and just mess about in the water, don't go thinking you are going for a swim, just go with the intention of having a laugh. Confidence in water is the number one barrier to people not swimming, and if you can remove yourself from the things that affect your confidence (usually what other people will think) then you will be more relaxed and enjoy the time in the pool more. I have found that the midweek swimming session usually just have 3 or 4 old ladies who are there to keep their circulation going, and they aren't in the slightest bit bothered by someone getting in the water to build up their confidence (indeed most have been in your position and may well offer words of encouragement). Just DON'T GET IN THEIR WAY, THEY ARE DEMONS!!!!
Swimming is a fun sport, have fun, don't see it as a chore, and once again I'll say JFDI....