u/ClassicWear6595

I’m a complete amateur looking for advice on my bathroom. I took off the tiles to re-tile, but the compound behind was completely failing on the wall that is now brick. I took this all back to be safe, and I’ve now started to try to get rid of all of the hollow/failing spots on the main wall. It’s getting to the point where my brain is telling me that instead of bonding around this, do I just take it back to brick which would take me 10 minutes, and use waterproof backer boards, then waterproof, then tile?

If anyone has any advice, or would let me know what they would do if they were on this job.

P.S. I appreciate the skill level and would happily pay a specialist for this part if I had the budget, but sadly I don’t, so DIY it is.