GreenGran78 please go for it.
I too have a phobia of deep water but I go swimming regularly at my local pool, and my trick is to keep to the lane on the far left by the side, so that you can hold onto the side if you need to. You can also use the side of the pool to do exercises in the water.
The water is so soothing, it clears my head and is very stress defusing. Swimming is one of the best kinds of exercise too.
Another tip is to have some lessons, and then go to the pool at a quiet time of day, so that you don’t get splashed or dive bombed by over enthusiastic children.
You don’t have to do anything spectacular when you have learnt. You can keep to the shallow end if you wish.
You will not regret learning...I promise you.
How do you acknowledge Easter.