It’s a good question.
I’m a convert to Catholicism from evangelical Protestantism, and so is my husband and daughter.
We don’t have problems with Marian devotion. But we know plenty of evangelical Protestants for whom Mary is a huge stumbling block. I understand where you are coming from on this. There are many Protestants who would walk away totally from the Catholic Church because of Marian doctrines that they refuse to accept. You have chosen to walk into the Church, in spite of your misgivings.
I think many priests would understand that even if you are drawn to the Catholic Church and accept that it is the True Church of Jesus Christ, it is still extremely difficult to change the mindset of many years of Protestant thinking and teaching and accept Marian prayers.
Catholics who are reading this, try to put yourself in the place of the poster. Let’s say that you were challenged to change a major doctrine of the Catholic Church–it would be difficult, wouldn’t it? There are people on this CAF who can’t even accept a Mass in English or sing a hymn in a Mass accompanied by a guitar, let alone a change in a major doctrine. It is really hard for humans to give up teachings that they have accepted as true and good all of their lives.
Hopefully as time goes by, you will find it easier, but as a new Catholic, you will struggle. I honestly think priests will understand this struggle, and be willing to work with you in regards to penance as long as your mind and heart are OPEN to becoming docile to the teachings of the Catholic Church.
BTW, my struggle with Catholicism is with the consumption of alcohol. I simply can’t accept it as harmless. Intellectually I accept that drinking alcohol in extreme moderation is not a sin, but in my heart, I still see it as grave sin to even have a beer or a glass of wine. I grew up in a teetotalling home and lived for over 40 years among Christians who never, ever drank alcohol, and I was incredibly happy with this lifestyle and these people as friends. So even though I accept the teaching of the Catholic Church with my MIND that alcohol is not a sin, I just can’t “feel” it is OK in my heart. So I stay away from Catholic functions where there is drinking, and I don’t socialize a lot with Catholics who drink alcohol. I wish that there were more Catholic teetotallers, and I wish that Catholics wouldn’t joke around about drinking. It makes me feel very uncomfortable to see something formerly evil now considered “good for the body and soul.” Yechh.