I would strongly suspect a breached head gasket, simply because this model is known for that weakness.
I would suggest having your mechanic perform a compression test a.s.a.p. in order to determine if you do indeed have a bad head gasket or two. Don’t delay, as it is also possible for coolant to be migrating into the crankcase oil. Since coolant is not a lubricant, this can spell a quick demise for the engine.