A Business prospect has not replied to my message and I want to reach out and remind him politely that I am waiting

So a few days ago I had sent a trial design to a business prospect who replied it was good but needs a few changes. I replied asking for specifics but he hasn't replied to my message.

I want to reach out and remind him politely that I am waiting for his response.

Here's the thing, this prospect is a referral and runs one of the biggest stores in the city so he might be busy and I don't want to sound too pushy or desperate. My business is struggling and I really don't want to blow this opportunity.

I have written the following but I am looking for advice to improve it. Please note that this is an SMS and not an email.

Hi Peter. Apologies for the repeated message. We seemed to have lost base since the last design I sent. You asked me for a few changes which I have done but I haven't heard back since. Could you please check if it is okay and let me know how we could proceed? Thanks

Please let me know how I can improve. Your feedback is greatly appreciated.