I dont like the 3bet here at all here tbh...especially with flatting for us being so perfect in almost every way. I also dont like your sizing, the fold by the opener is terrible...and you almost always are going to be going 4 way here in a bloated pot with a weak (often dominated) hand vs 2 calling stations and a decent guy IP on you. So what does this achieve? I would much prefer a sizing of 135-150 being so deep, at least then you get the button to fold a lot more.
The situation we are in when we decide to 3 bet is pretty perfect IMO. There's roughly 120 in the pot and 25 to call, for almost 5-1. We have a hand that flops decent. We have relative position on the PF raiser, and absolute position on the two stations. On top of all this, when we get 4 bet by the opener...it is a DISASTER.

As played you have to bet for value. It's a fairly ideal flop for us, but we still need a little bit of protection. Your repping a strong range, so you can't assume either villian to open up their bluffing range on the turn if you check back...especially with it being 3 way. So im not really seeing what a flop check does for us here. Maybe if they were overly aggressive and spazzy i wouldn't hate it, but as you said they are stations, so value betting seems like a no brainer. I'm betting 180-225 here and checking back a lot of turns to open up their river bluffing range/bluff catching range. It's about as dry a flop as you can get, so i would expect our cbet to win a huge percent of the time...and to see a ton of Q10/QJ/QK when called.

"My image is bad because my last straddle attempt failed miserably. But I'm not one to give up. I straddle and find Q♥ 9♥" And then you get out of line again. Foolish.

Overcall pre, try to hit a miracle hand or a decent draw and then start playing. At this point, you probably have to check and call against 1 player, fold against 2 or more. Your hand is not worth valuebetting bc ppl should defend tighter in multiway spots.

3bet sizing is really bad, amazed we got a fold here. When my image is "bad" I generally tighten up until I show down some winners especially when in a pot with stations. Stations like to call so why are we bloating the pot with a marginal hand that is often dominated by the hands they call a raise cold with OOP? If this 3bet is a steal attempt then pop it up bigger.

The fact that you are asking what is our plan now is the real glaring issue with the play. You 3 bet small, got 2 calls, flop the stones and aren't sure what to do. HAVE A PLAN. Know which flops you are betting and which you are cking. Seems like an obvious bet for value on this flop but again our Q may be dominated if we get much action.