Web mail delivery issue + Profile and gig optimization

I'm a web hosting reseller cpanel based using Webmail and have not received any emails for the past 6 months in my primary domain hosterpapa.com but clients on other accounts receiving emails without issues. My current provider has been unable to resolve this issue. I need someone who can fix this problem. The solution should ensure that my emails do not end up in spam, and that my email system remains well-reputed (any one who have proper unlimited email service/server can connect me with their server minimum 5 year should receive email later on in my cpanel this job is main) i am expert but still not able to resolve that's why posting here.
I want to optimize my fiverr gigs + upwork + freelancer.com including required banner and whatever required i should get order their. lowest budget no money
Requirements:
• No additional plans or subscriptions for email required have not money
• Emails should be delivered to the inbox, not the spam folder
• Gigs and profile should comparitively improve and i see good results as well then i will pay otherwise not
Website fixes recommendations also appreciatable
I'm currently using Webmail as my email platform and utilizing SPF and DKIM for email authentication. However, I have not checked my domain's blacklist status yet. Please only apply if you're confident you can solve this issue within the given budget.