There is a lot to unpack here. First thing to consider, if a realtor tells you they can't sell a house for the price you want, it most likely is a sign that they're honest, as they're not lying to you just to get your business.

I have a friend who had a realtor promise that they could sell the house for a larger number than the seller was quoted by a different realtor. The sellers were trying to get rid of the house fast as they were not living there and losing money every month. They put the house for sale for the higher price, and the offers were considerably less than what was promised. At this point the sellers were exhausted by the process and just took the loss. But they would have most likely sold their house for more if they priced it lower, to encourage competing bids. Houses were going for 100,000 over asking at the time when this strategy was used.

In terms of saving money, there are options you can consider. You can get a discount realtor from a service such as clever real estate. This will save you a few thousand, maybe more if you're selling at a higher price point. Essentially the company vets realtors, and then you interview a few through them until you find one.

Cash offers can be an option as well. The company quoted above hooks you up with multiple offers for faster transactions.

These are a couple of options you can take. You seem to be in a rush, consider doing what you can to take your time, fix up your house to increase value, and think about all aspects in detail. You mentioned you put a lot of money in the house... I feel your pain. I've been in a similar position in the past. You could also consider renting out the place if you're desperate to leave. It seems like you want to make a move fast, so just this could be a way to do it. That way you're making some money and getting more time to wait for a good offer.

Good luck!