I know you sent a private message but I wanted to answer here in case anyone else had anything more to add. I am no expert but can only think of the following:
1) You should definitely consult an immigration expert as your case can get complicated. Even if you just consult them before sending off your file, they can guide you on how to disclose this information.
2) NEVER ever knowingly hold back on any information as it can have huge negative impact on the processing of your case.
3) In your case they might think your marriage is one of convenience because you have tried previously to settle outside of Pakistan. I would recommend send them lots of proof of relationship. Pics, receipts of shopping, wedding hall receipts, wedding clothes and gifts receipts, gifts sent to one another, phone calls, video calls, emails, text messages, social media accounts showing each other as husband and wife, letters from family and friends who know of your relationship and attended your wedding. Pics from honeymoon travels or any trips taken together.