It looks to me like the plants are growing tooooooo leggy because they are stretching up towards light.
All delicate thin stemmed plants topple in the rain especially heavy falls as that adds weight to the foliage and the flower heads / buds get saturated too, causing them to become top heavy however, most plants can then stand back up after the foliage / flowers dry out a bit, I sometimes go around and gently shake the rain off the plants allowing faster recovery.
I would bring the plants further out from the shade they are receiving overhead, add some canes around the edge if the pot and intertwine soft flower string criss crossed around the canes to help support the flimsy tall stems, as for next years flowering's, make sure they get good light and some form of support, normally when planted in a border / bed, these plants benefit from the support of their neighbouring plants to help support them.
Hope this can give you some help and the plants give you further pleasure for the rest of the season.
Best regards. WeeNel.
These seem to love hot, searing, egg-frying Texas sun, and are more bushy. Give them as much sun as you can. If you decide to trim them to encourage bushiness, stick the cutting in damp perlite. My mother has pretty good success with rooting them this way. (Me, not so good -- probably because I usually forget them, and don't find them again until they are little gray crunchies.)
Though they can be smaller shorter and fuller in more sun, yours are very attractive as grown.