Being frequently disconnected from several different WiFi’s....

I am using an iPhone SE on iOS 11.3. In the past months I have frequently had struggles with staying on WiFi networks including hotspots, home networks, and hotel/building networks(currently trying to deal with one at a Disney resort). Usually within one to two minutes of connecting to ANY WiFi I will be disconnected. This not only causes me to plow through a tremendous amount of data, but for many sites and apps switching between WiFi and data is troublesome for videos and streaming, which requires me to refresh, or exit. I can confirm that this is not due to movement, as it happens just as often when I am stationary. If there is a solution to this bug that doesn’t require me to get a new phone- then I greatly appreciate it. This has been causing me to be up to four times less efficient with time which I would really like back because I am a student.