I haven’t read all the posts here, so I apologize if I am re-stating something. Also note I am not a vocation director, I’m a humble lay-person.
I started seminary a month ago, after getting a four-year computer art degree. It wasn’t an impediment for admission. At Sacred Heart, there were around 25 new seminarians in the undergraduate program this year, maybe near 30 (I lose count). Only one does not have a degree, and he came right out of high school. Everyone else has at least part of a four-year degree. Two have degrees in philosophy already, and they still do two years of pre-theology, but taking higher level classes. One guy has a masters, another has a partial masters in business.
The low number of pre-theology guys this year with no college degree at all is a little atypical. There are I think six or seven guys who came in at previous years in the 4-year college program without any college at all; one last year from our diocese transferred last year with a partial degree, but not everything transferred.
So no, you don’t need a college degree before you begin discernment. However, most religious orders will require some theology, which has a philosophy prerequisite. The priesthood has a 4-year theology requirement as per Vatican directives, although some orders have different ways of doing this than diocesan, and dispensation can be given, usually only for men, over a certain age (usually 50–our pastor was one, but he was a permanent deacon before hand too. those exceptions are rare.)
If you are considering a vocation, call your vocation director soon. He will be able to better direct you as to what you should do. This close to graduation, he will probably advise you to finish your degree if there are no issues preventing it.
Continue to pray and be open to the workings of the spirit. The Lord is a wonderful shepherd for those who hear his voice. Be ready for anything.
You are in my prayers.