If swimming is just something you do for fun, consider cutting back on swimming and running SS as-written.
If swimming is your first priority (i.e. you compete), you might try just doing SS 2 days per week instead of 3.
Ideally arrange the days so that you don't do barbell work the day before swimming.
The obvious alternative is a less-stressful "intermediate" program like heavy-light-medium or 5-3-1.
The problem with these is that they are customized for a single lifter.
You are supposed to have been lifting (and recording data in your journal!) for months before starting an intermediate program, and now know something about designing your own program.
The books about them, like Practical Programming for Strength Training are textbooks on program design, rather than a simple recipe to follow rigidly.
Beginners are generally *terrible* at making up their own programs.
Fortunately, they also gain strength really easily, so can make progress for a while even with bad programs.