31 weeks feeling sad

I’m 31 weeks pregnant. I’m 20 years old I’m going to be a single mom for the last week or so I’ve been feeling pretty down like between feeling over being pregnant and my body being in pain and tired, plus working a full time job and being ready yet still nervous to give birth and for what’s to come after I just want to cry all of the time. I feel like it just recently really hit me that the baby’s father won’t be involved and I wish he would change his mind because I really don’t want to do this alone. I feel like I’m missing him more than ever now but I don’t see the point in reaching out when he hasn’t replied in months. I just hope when the baby gets here I’m happy and I stop caring about him so much and am just so in love with my baby that nothing and no one else matter. I guess I’m just looking for kind words of advice or anyone with experience with something like this.