I really feel for you ... What a $hit of a time you are having. You deserve to enjoy motherhood
I hope this doesn't come accross as too blunt. Because I really do think you are a wonderful lady and hope things gets better for you.
You need to get help for and keep on top of your anxiety. I think this is at the core of the issues with poor bubba not sleeping... Bubbas are sensitive little souls and no doubt bubba can pick up on your stress levels. I know my toddler does when I am stressed (but that's a whole other thread!). Stress and anxiety also cloud your judgement so you probably aren't using the most effective methods to put bub to bed.
Over various threads people have offered lots of different hints and tricks. You have had a sleep consultant come and visit. You have a tool kit that is bursting at the seams and a bunch of people on BH in your corner. You just need the clarity, calmness and confidence to move forward. Oh and consistency... Don't give up on a new routine/strategy after one or two tries. It can take a week or so for new strategies to gel with bub.
Wishing you the best of luck.