8 year roller-coaster
Sorry for this tough time.
I'm a strong advocate for a partner to still go to counseling/therapy even though their other half isnt interested. Thete is a strong possibility you will not reunite so those appointments will assist you in that process. It can also help to clarify whete your partner is unreasonable in his treatment of you. Clarity.
What we also have difficulty with is "how can I get him to open up to me"?...you cant. Humans make their own choices, some are mistakes, some silly, but everyone does their own thing. If such actions/inactions do not satisfy you then you can consider how you deal with it.
Im 63yo. At 28yo I had had a 7 year relationship. She still could not commit to me nor wanted kids. I had to make that gut wrenching decision to leave and seek my life goals. Of course I loved her. It was hard.
Over time the pain drifts and love will come along.
Remain strong, dont do rash things and love what life has to offer.