Shall I pay for swimming lesson

I don't know how to swim and I have arranged private lesson with an instructor next week. The thing is I don't really go to swimming pool, I just go to the beach with my fiance once a year and we go there 2 or 3 times during our trip. The cost has come to £25 per lesson and its not something I can really afford but doable. I just felt so embarrassed last time when we went as I couldn't swim I just got in the sea where my feet touches and basically walked my way all the time. The question is is it worth learning to swim even though we go once a year and I don't ever go to pools.