If it’s something I’m (still) wanting, why would I give up? I might seek guidance on a better approach or do some supporting rituals if they seem to be needed, but if it’s wanted/needed, I will continue.
Some of my lifestyle workings have supporting workings that need done, too, before they will (likely) be in the spot I want. This can take years for some of these, in my opinion. That’s fine with me. I could likely make it happen with money by then, so I’m not as concerned.
In general, I won’t think twice about needing to recast something, just in case more energy was needed than when I cast (for whatever reason). I usually deal with complex problems (many are, under the surface), so I don’t go in with a one and done mentality (I’ve cast a dozen times before to keep momentum and build in that type of working). I don’t take it personally, but sometimes get discouraged. But if I give up on it, while still wanting it, I can’t expect anyone else to do the work for me. Unless they’re a good friend with some extra time 
I’ve been working one project for a year now. Super complex and things are outside my direct influence daily. I simply reevaluate, adjust my approach, and continue.
Another project is showing promise after … months of making small changes and letting it trickle down. Quite please, nice start. It’ll need to be maintained until the end goal is met.
Some of the people on this forum have seen things work in hours, days, and weeks. All depends.
But if you really want it, seek guidance on the approach from an appropriate spirit and continue. Also nothing wrong with asking others for help. It’s promotion season at work again and I reached out to someone that offered help for it in the past. I may reach out to others, too. I’m not too proud go that route, so I would use it f it may help.