Feeling Guilty

I just wanted to reach out to see if anyone else feels the way I do sometimes. When I go and spend money on myself, this strange feeling of guilt comes over me and idk why. If I get a mani/pedi or buy new shoes or anything for myself I feel so bad. I just feel like someone else could use that money or I could put it towards bills. Even when my SO gives me money to spend on myself I often tell him to hang on to it just in case we need it. I really don't mean to seem unappreciative. I really don't know why I feel that way sometimes lol. Do any of you feel this way when you do something for yourself?