Is it normal for your foreskin to be attached at the tip of your penis?

No, that is not normal. The foreskin is normally attached only at the base, so that it is able to slide back to expose the penis, during sex (for greater sensitivity). If it is actually attached at the tip, I would suspect that it just got stuck by some dried residue, but if it is attached by skin and not just by glue, consult a doctor.