Sendgrid code help for Gmail responsive

Hi everyone! I am a graphic designer using Sendgrid to send emails. But sendgrid don't have a function where we can show 1 image size on desktop and another image size on mobile responsive devices. Also, they don't allow us to design an email that has a column that is 500px wide and one that is 300px (or the % equivalent to that). SO, I went into Mailstyler and created those 2 sections we needed and added in the code to SendGrid (which allows for sections of code to be added in). Done I thought- but no!!! It appears fine on Outlook and Gmail desktop and mobile Outlook BUT NOT ON gmail mobile responsive. SendGrid have been absolutely useless- their technical department saying they do not handle these problems. Not sure if there is any help you can give me!! Below is 2 sections of code that come from Mailstyler. Without these 2 codes SendGrid works fine on Gmail, but we need the design that this offers.