Is this sleep regression BACK!??!

I'm really confused, frustrated, and tired. I already have horrible sleep habits. I wish I read about healthy sleep habits before he was born, I never even knew this was an issue. He currently nurses to sleep and can only nap in his swing. All day today as soon as I put him down in his crib he wakes right back up and cries. This started happening a few days ago. Before this I was actually able to put him down drowsy and not nurse him to sleep or use the swing. He even took a pacifier a couple times. Now it's as if he's back to that regression I just went through for weeks! What the heck is going on???? Can I ever get good sleep habits for him without him having to have a total meltdown 😭 he has tears within minutes of waking up, idk what is going on. I don't mind letting him fuss it out but he absolutely cannot soothe himself back to sleep even though I've seen him do it previously. He is 20 weeks 4 days.