How to let go ..

Since my child’s father I’ve been single (3 years) finally let someone I thought was a good person in and realized they mean me no good, after breakup I feel sick , I can’t eat I can’t sleep feel disgusted and just want to throw up

I never even felt like this with my child’s father, how do I let go for good ? I feel like I want to hold on so bad because I never ran into someone I liked or wanted , it took 3 years to date again and I got let down

I’ll blow up his phone and he will ignore me, I’m 21 years old I know I’m still young but it’s so hard to come across someone I like or interested in

I’m so unhappy in life I fight depression and I only stay strong for the sake of my child and people don’t understand that so coming around with no good intentions only makes it worse. Like I’m actually a good woman I just want to be able to feel nothing ,

I literally can’t eat and when I try to I think about it and instantly lose my appetite