wanted to visit canada to get married to my fiance but refused

hi,
i m a Pakistani national living in UK for past 5 years and studying full time, my fiance lives in Canada(she is a Canadian national) now we have plans for our wedding and date has been decided as well, my in laws sent me all the related documents i.e their current bank statements, property papers, copies of passports and an invitation letter stating that they are inviting me to get marry to their daughter.
i included my bank statement, letters from college stating that i am a full time student and currently studying, letter from my employer ( part time work) along with a completed application, but still i have been refused for a TRV, and visa officer mentioned only one thing in refusal letter that i don't have strong ties in my country of residence(UK) and i might not come back, i am all worried now as date is not far and i did not have any intentions of not coming back since i need to complete my course which needs another year, but visa officer did not give me any right to appeal, can anyone please advise me what should i do and what new documents i should include if should i re apply, help would be highly appreciated , thanks