You can keep amaryllis and get it to re-bloom next year. The key to getting your plant to do so is keeping the plant actively growing after it has finished blooming. The University of Missouri says:

Re-blooming amaryllis is relatively easy, but the plant must be allowed to manufacture and store food in its bulb in preparation for the process. This is accomplished by exposing the plant to light as bright as possible during the period that occurs after flowering has ended. Adequate water and fertilizer are essential for maximum food production during this period. After the danger of frost has passed, moving the plant outdoors into a lightly shaded setting will facilitate growth and improve subsequent blooming. In September, the plant should be brought indoors, and water withheld. This will induce dormancy, which should be maintained for several months. During its dormant phase, amaryllis should be kept on the cool side and should not receive water. The leaves will wither and dry during this phase and may be removed. The growth cycle (along with blooming) can be repeated by forcing the plant out of dormancy by watering and subjecting it to warm temperatures (minimum of 70 degrees F. during the day and 60 degrees at night is ideal).” (https://ipm.missouri.edu/MEG/2018/1/amaryllis/)

Sources recommend maintaining dormant amaryllis at temperatures between 50- and 55-degrees F. Some sources recommend keeping the plant in complete darkness; others say semi-dark. Plants should be kept dormant for at least 8 to 10 weeks. Iowa State Extension says another option is to place the plant in a well-lit, 50-to-55-degree F. location in fall. Maintain the amaryllis as a green plant from fall to mid-winter. After the cool requirement has been met, move the plant to a warmer (70-to-75-degree F.) location. Below are some resources that can guide you step-by-step through the process:
https://hortnews.extension.iastate.edu/faq/what-should-i-do-my-amaryllis-after-it-done-blooming
https://txmg.org/mclennan/2011/03/22/amaryllis/
Growing and caring for amaryllis.

If you have any gardening questions, please contact our DCMG Help Desk by emailing us as dallasmg@ag.tamu.edu.