Mazal Tov, Mazal Tov
i do not think it is forbidden (since you are damaging your body for a reason; a good reason might be to get pregnant form the first relations, (see yevomos 34b, audio but it is possible Tamar did it when she was with Yehuda and did not need to wait 7 days because it was before the decree of the besulin blood)) and it might not be damage since you can do it on shabos (but it might be Baal Tashchis)),
but a woman that does it is surely lowering her worth and her connection with her husband. If she feels that she needs to do it I think it would be proper to get permission from the groom.
See shulchan aruch even ezer 67.5 that her kesuva is half of the one for a virgin (meaning: hymen intact) girl.
See talmud sanhedrin 22b that her relationship with her husband is less intimate
R. Samuel b. Unya said in the name of Rab: A woman [before marriage] is a shapeless lump,3 and concludes a covenant only with him who transforms her [into] a [useful] vessel, as it is written: For thy maker is thy husband; the Lord of Hosts is his name.4
3 I.e., of undetermined character.
4 Isa. 54, 5. As God formed the character of Israel so does a husband that of the wife.
from shulchan aruch even ezer 63.2 we see that there even is halacha that the groom says borcho (some say it without Hashem's name) if he found the hymen intact (and it seems some say it over a cup of wine)
see a disrespectful translation here (the shulchan aruch really respected the Rambam (see there) but still decided that there is an obligation to say it.
Comenteries on the brocho see prisha even ezer 63 and aruch hashulchan 63.10
regarding "caused them panic attacks"
maybe if they have in mind that girls used to get married at 12 (the hymen was more intact (probably more pain)) it will help
regarding "break her hymen by herself in order to minimize pain"
why would this minimize the pain?
if there is a way to minimize the pain, maybe tell it to the grooms teacher .
regarding "shame upon consummating her marriage"
from a Torah/Jewish prospective, it is much more shameful if you do not have one,
(what shame are you referring to?)
Regarding you personally we support you, and wish you success and all good, and a keziva vhasima tova lshana tova umisuka for you and your groom
P.S. maybe if you have in mind that only G-d exist (ain od milvado) it will help you not to panic