Hello and thank you for your question. You can still contribute. I would recommend to look at traditional and roth IRAs, including a SEP plan since you are retired and self employed. Included links below for both options. The first one has to do with contribution limits and the second has to do with a SEP plan since self employed as well. Have a great day!
From IRS "IRA Contribution Limits"
From IRS "SEP Plan FAQs"
