Help – my dog has become very fearful on solo walks, how to rebuild her confidence?

Hello everyone!

I'm desperate for some help with my dog, who has recently become very fearful and apprehensive on solo walks with just the two of us.

TL;DR: my 2 year old chi mix has recently become quite fearful on walks, even though we used to walk miles together daily without issue. We've ruled out pain, and she walks happily with other dogs and people in the group, but solo walks are hit or miss. Any suggestions for getting back to normal?

The details –>

About my dog:

• ~2.5 years old
• Chi mix
• Owned since 10 weeks
• No fear/anxiety on walks previously, she has always enjoyed daily walks and likes a lot of activity in her day

About the behavioral situation:

• Started about 2 months ago
• A few things happened all at once:
  • One scary trip to the beach where there was a lot of activity and she got overwhelmed
  • I sustained a back injury and wasn't able to walk her for a few weeks
• After these instances, when we tried to get back to our 'normal' walking routine, everything we encounter sends her into an anxiety attack

The behavior:

She wants to go for a walk, we leave the house, make it a few blocks, and then inevitably, we'll encounter some noise, person, etc. that will trigger her. She then wants to rush back home and has a difficult time coming back down from that anxiety.

What I've been trying:

• Short, slow, sniffy walks around the house with lots of treats, ending on a high note
• Walking with other people and dogs both in my neighborhood and away from home (again, she's basically fine/normal when other dogs and people are present)
• Resolving pain – she has luxating patellas, I've been advised against surgery, but we are doing a course of NSAIDs to rule out the impact of the discomfort
• Chatting with a trainer – she recommended ruling out pain, but didn't have any other additional suggestions

I don't want to go the route of permanent meds at this stage, as she's not generally an anxious dog.

Any help or advice you all can provide would be so appreciated! I feel so bad for my little dog, I hate that she's going through this and would do anything to help her, but I just can't quite figure it out.