Sleep help

I need major sleep tips here..

my baby is 5 months old, and I think her (4month regression) is happening now rather than at 4 months.

From birth she was always such a great sleeper, 10-12 hours at night no problem.

Now...

she is up EVERY hour.

The past couple nights I kept her up till late because she just was refusing the sleep!!!

Than I said enough is enough yesterday she was in bed by 7 but again up every hour until 11:45 and then slept through the night which is awsome

I try to let her her cry it out but after a while I can’t do it anymore my heart aches so I pick her up.

So o assumed maybe it was too early so I delayed everything tonight and gave her last bottle at 7pm and tonight she fell asleep at 745 during the feeding put her in her crib but was up at 8 crying and crying.

I pick her up hold her put her back she. Plays for a bit in her crib etc etc than starts crying

I’m not sure how to sleep train because this is my first baby, I do want her to sleep on her own.

Just so lost and not sure what to do. I’m so frustrated and feel so guilty for feeling frustrated.

Am I the only one dealing with this ?