Sounds like you're going about things in productive manner. Practice needs to be about you, not what people think about you. If I get a little rusty, I'll spend three or four (sometimes more) games where I do nothing but shoot at one corner pin on the first shot and the other corner pin on the second. I've had good-intentioned people come up to me during such a practice session and say "You know what you're doing wrong?" when I was in the middle of a 40-in-a-row streak. Truly knowledgable people will recognize what you're doing and leave you alone.
Good luck. With a little work and perseverance, I'm sure your spare conversions will increase.
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Kill the back row (or maybe this should read "make your spares, dummy")