Career gap

Hi all, 

Would like some thoughts on how to present a resume gap. Things have been slightly rough for me over the last 2 years

1. Initially had a strong background in Big 4 TAS and Mid-market M&A (c.6 years in total)
2. Left to go to a regional LMM PE fund (only lasted a year) before we both had a conversation about it not working out, given the commute (left on good terms)
3. This was a year ago and since then, I accepted a role with another mid-market M&A bank which lasted only for 3-4 months before I was fired (was pretty desperate and completely misread how slow the market would be). 
4. I accept a lot of responsibility for this one - it's just once I moved to the buy-side, it was honestly impossible to go back to the ways of banking. I'm now working on an interim basis within PE-Backed corporate development (coming up to nearly a year since I left the LMM PE fund). Issue is there is now a 2 year period where I've had almost 3 jobs and none of them have stuck. 

My confidence and mental health in the last year has taken an absolute pounding. Felt I was on top of the world 2 years ago and now it feels I'm heading into no mans land. Very far from where I thought I would be in my career and I'm not sure what to do next. Even the fact that I'm working on an interim basis is still giving me uncertainty and its hard not to think that my career is finished. Another issue is that technically I feel quite stale now - I don't have the latest deals I can talk to on my cv and it's been nearly 15 months since I last did a completed deal. 

What do you recommend I should do? Stick it out in the interim or continue applying?