Good Days They Want All These Things With You And Then Bad Days It's The Total Opposite. Why??

Hello All! Advise please, both Sufferer and Supporters (I hate using those terms). This is what I don t understand, especially after 1.5 years... One minute you are the best thing that has ever happened to them and they want to marry you and planning a future. Then the triggers come, the anger strikes and they want nothing to do with you or the things they said they wanted previously, they isolate. Then a couple of weeks later you get, it hurts or I miss you, I love you more than... Good Days They Want All These Things With You And Then Bad Days It s The Total Opposite. Why??
https://www.myptsd.com/c/threads/good-days-they-want-all-these-things-with-you-and-then-bad-days-its-the-total-opposite-why.69825/