This is a very serious issue for you. Are you sure it is procrastinating or is it waiting until you are ready?
Before you tell her, think out the worst things that could possibly happen or that she could possibly say and prepare your responses to them.
Also, be clear about what you want from her and tell her. Do you want her acceptance of your homosexuality? Do you just want her to know so she knows who you really are?
She will be confused about what you expect her to do or say so let her know. Maybe it’s “You don’t have to say anything now, Mom, just take some time to think about it.
Is your Mom supporting you? If so, you have to be sure that if she were to react in an extreme way and toss you out that you have a plan and that you are OK with that before you tell her.
Good luck. I am hoping for your sake that her love for you will triumph over her fears.