Oh my love my heart goes out to you at this time. When it comes to love it’s often messy and complicated and no doubt so was your relationship with your ex.
You can’t turn off what the heart feels and at times it sucks but he was the father of your kids and with time it’s normal to remember the good parts even if you are aware of the bad.
You have every right to be at his memorial, if only to get your closure and put to bed the past and move onto your bright future ❤️❤️❤️