I feel like there are too many important differences between the two, and can’t connect with anything spoken or written by Protestants the way I used to before I got serious about my faith.
I think you should apply what the Church used to more openly teach about this: refrain from reading materials written by Protestants which are overtly about Faith or morals, don’t listen to sermons by them, and don’t go to their services.
This is not meant to be a slight against Protestants, but is in keeping with an obligation each Catholic has — don’t expose yourself to materials that could undermine your faith, and don’t think you know so much, or are so well-grounded, that you’ll be perfectly fine no matter what sort of religious material you read. To do those things without truly sufficient reason, in most cases, is venially sinful, IMO.
While its obviously true that Protestants are Christian, it’s also true that the various Protestant sects have beliefs which, for one reason or another, happen to be heretical. As such, they can present us with an obstacle to the proper understanding of truth, as revealed by God through His Church.
Look, people are so quick to mention that this sect has this truth, or that that religion has these 17 solid doctrines. But how on earth do we know that? Frankly, we know it because those things are already taught by the Church, and therefore we recognize them as true. So why don’t we just stick to the Church, and leave the error aside. No one in their right mind would eat a spaghetti dinner because it “only” had a little bit of antifreeze in its sauce. So it should be in our approach to sects or to other religions: “only” a little error is too much.