Overwhelming feeling of sadness

I broke up with my gf of 5years due to lack of love being reciprocated and attentiveness was not shown. Lack of communication and past traumas holding us back. The pain and distress and sadness I feel has got me in a chokehold. I’m not like seeing a way out of this feeling. Ik people say it takes time and energy Will shift but I’m missing her like crazy and I just want to text her and say I’m sorry and not get back together but just know how she is and if she’s eating and feeling and sleeping. Ughhhhhhhhhh