Agreed @housethatbuiltme , I didn't have anyone trusty to alter my dress either but you just find a professional and factor it into the cost.
I think it's hard for anyone to comment OP, we don't know your size or style. Ignore your age and what you think a 46yo should wear. If you want to wear a Ghost dress, do. (Incidentally I planned to wear the Ghost Claudia dress for my wedding, but in the end found a Justin Alexander proper bridal fit and flare mikado satin dress that was a much better (albeit much more expensive!) choice.) I don't think it being 'very you' or predictable is necessarily a bad thing, if you have a set style.
I don't know your budget, but if it's high street but reasonable then I'd look at Reformation and also TH&TH. This is gorgeous from Reformation and not predictable at all. If you have a bigger budget, I'd find a bridal boutique that stocks styles and designers you like and get a 'proper' wedding dress. They don't have to be fussy, mine was similar to this