I have tried to convince my mom to go to therapy also. It hasn't worked. Her doctor has tried too. Her insurance will pay, but she saus she can't afford the copay or the time off.
I have tried to convince my step-dad to go to GA and my mom to Gam-anon. They used the excuse time and money. So I printed out times of groups on the weekend and proved they were free. Didn't work.
I'm trying to convince my fiance to go to therapy for his anger, stress, and communication. He did go to an anger management group for a little while until they had a session including spouses and I found out the guy was a quack

Now I'm trying to get him to go to individual therapy. My T and Pdoc want him in therapy too. So far it's a no go
Many people have misconceptions about therapy. Many are also okay living in their current state because it's familiar. The only person you can change is yourself.
My T gave me this advice: to continue to work on myself. Either the person will see the change in you and will want to grow with you or you will grow apart. Either way, at least you will be taking care of yourself.