Gmail [0] ignores dots in your email handle and so you could use a different pattern of dots for each website you register at and record it in a spreadsheet or something. The first and last characters cannot be dots, and I do not think you can have two or more dots in a row, but there is no limit to how many "legal" dots you can use. Not as elegant, but definitely doable.
[0] https://support.google.com/mail/answer/7436150?hl=en