The meaning is the same. "Μήπως" is used in a question and "ίσως" is used both in a question and a normal sentence. It's more common though to use *μήπως" and not "ίσως" in questions. Examples: -My tummy hurts. -Μήπως/ίσως έφαγες πολύ; (rom: mipos/isos efages poli?, trans: maybe you ate too much?) or -Ίσως έφαγες πολύ. (rom: isos efages poli, trans: maybe you ate too much) In the text that you wrote the correct is "ίσως" because in that case it's not a question but just a statement you made about yourself. So in conclusion, we use "ίσως" for both questions and normal sentences and "μήπως" only for questions. I hope it helps!

Πολύ ενδιαφέρον απάντηση μου βοήθησε και για εμένα