Will I feel like this forever?

It's been three months since my daughter's father left us for some girl he met through Twitter. He hasn't contacted us (besides to harass me) and neither has his family. they all just stopped caring, they've already met his new girlfriend and he's giving HER the life he couldn't give me and my daughter. (They're moving in together after 3 months of being together) Hes said hurtful things like he's never loved anyone like he loves her, and I was just a mistake, when we were together for 6 years. I haven't felt any better, I've been so sad over this. I just feel "stuck" and as if it will feel this way forever. I've been seeing a therapist, it's helped a little but not too much.. I've also blocked him from everything. Has anyone been through something similar? How did you get through it? Does it really get better?:/