I think regret is normal during a breakup phase and it will go away in it's own time. For a long time I regretted some things with a ex, but I did reach out and I just got burnt again. Not saying it would be the same for you... keep your head up, also the grieving stages are not necessarily in an order like they can happen in different orders sometimes blending more than one at a time.
I'm sorry for your loss and pain. I'm an empathetic too and can literally feel your remorse/dread right now. Send yourself love.
