No problem, I suspected that is what you meant but just need to confirm all facts.
In FL there is no "breach of trust" unless there is a formal trust with a trustee involved. You could, theoretically, make an argument that the money was given to her "in trust" but without written documentation I don't think it will apply.
You could, again in theory, sue your wife for a breach of oral contract
but doing it outside of a divorce is going to be extremely hard to do for a number of reasons.
It sounds like a divorce is in the works anyway so the most economical, realistic solution is to sue to have the court impose a "constructive trust" over the money you gave her and ask that it be returned. However, there are a couple of issues you need to be aware of.
First, the court may make the assumption/presumption that the money was a gift. Unfortunately, "security deposit" written on a check doesn't really do much to support that it was not a gift, particularly when you said "We agreed the money would be spent to help her move out if we split up..."
She actually has not right to any of the separate property money, but in this case I think it is at least feasible that the court is going to say that since you "made the agreement" and are now asking her to move out then she gets to keep that $5000. Since the rest of the money is separate property then the court really doesn't have jurisdiction to give her any of the rest of it no matter what she wants.
You could argue that by her being "verbally abusive" she now as "unclean hands" and isn't entitled to the money. I think it is going to be a hard argument but it is really the only one you have.
As far as the living arrangements you could ask the court to let her keep the place and give you the money back since the money was expressly to help her move out and get a place of her own. Again, you argue that because she refused to do so she has forfeited the right to the money due to "unclean hands" and you should be able to use it to set yourself up in a new place.
Please ask any follow ups in this thread.