Dad in need of advice/shoulder to cry on

So for context ive been dating my partner for 8 years in December. She has a daughter from a previous relationship she is 12 ive been in her life since she was 4 and her have a daught together that turns 4 in September.

Recently my step daughter has been experiencing very severe anxiety and I was in the middle of making changes to my parenting style ive been a stay at home dad since the youngest was born and my attention was mostly on her until she gained some independence.

I didnt have a good role model and didnt prepare to be a dad when the stay at home option became available.

This has come to a head 3 weeks ago when my step daughter voiced a plan to my partner to run away. She said I was a big contributor to her anxiety and havent been a good dad. I admit I haven't been perfect snapped when I shouldn'tve and didnt have the patience to talk instead of just yelling or sending her to her room. On top of just coming out of the infant and early toddler stage my attention was split between the youngest and keeping the house together.

My partner asked me to move out to give my oldest space and I didnt contest and packed my bags ive been in a shady motel about 15 minutes a day and still try to come by help with house work, take care of the youngest and the oldest when shes having a good day.

But even tho im willing to try make it work and fix the trust ive broken with my step daughter I am really struggling mentally im nearing a breaking point, physically I havent eaten or slept in days. My mental health and past truama is eating at my rational thoughts and i really just dont know what to do.

I face time my youngest every night and watch her cry for me to come home my partner is on and off with affection I know shes torn between me and her child and thats just an impossible place to be.

Just having a winge but any advice is appreciated