Hi, L..
Good for you for making and freezing your son's food! I can tell you're committed to his health and well-being, and that's such a huge part of being a great parent.
Babies and toddlers go through all kinds of cycles, and it's completely normal. Some doctors are more freakish about it than others, pressing you to shove food into the child so they gain weight along the chartlines. 8.5 months is a little young for all those solids--yes, the doctors and pretty much everything out there says to start by 6mos, but there's a whole school of thought about slowing down that whole solid-food introduction. Check out Attachment Parenting International, La Leche League and Dr. William Sears' websites for more info and details about how to handle this.
Just keep an eye on him for signs of hunger, and then feed him what he'll eat. If you force-feed, they can grow up with food issues or not know that it's ok to stop eating when you're full.
Both of my kids (13 and 3) go through the eat/not-eat cycles, so we just adjust what we're feeding them. I think they just live on air at that point, while their bodies focus on developing something else. The baby's gone back to a baby-food/nursing-only diet for now, which is a little frustrating--who wants to feed a 3-yo baby jars when you know she'll eat our dinner?--but she refuses our food to the point of not eating at all, so we just give her the jars (and I nurse) to be sure she's getting the nutrients she needs, and trust that she won't be eating baby jars in college. :-) She tells me she'll still be b-feeding in college, though. Ha. I am not a supporter of parent-led weaning, but I WILL wean before that. ;-) She still nurses many times a day (I don't bother tracking it anymore), mostly before/after nap/bedtime, but also as comfort or boredom breaker--that's when I try to distract her with juice or snacks or a meal, but I don't force that if she's insistent on b-feeding.
Soft-cooked peas can be a good finger food, especially if you make fun of chasing the balls around the plate. Itty-bitty bites of toast. Raisins (one at a time, because suddenly they're a choking hazard--they weren't when my 13-yo was a toddler, and everyone let their kids suck down baby handfuls of them). Cheerios. Babies R Us has a ring with a mesh attachment. You put soft/cooked fruits/vegs in the mesh, and the kid can gnaw on it and get the juice and mooshy pieces through the mesh, ensuring the nutrients get into them, without the danger of choking. This was a big fave of my now 2-yo.
Good luck!