It's many years since my airbrush experiences but I think you are using too much solvent and not enough pressure…try experimenting by spraying into a plastic cup… I saw your other post re air reservoir. If your comp does not have one you can experiment by inflating a car spare tyre and tehn connecting the air brush….inflate to 40psi. As ever, a regulator with a conbined moisture trap is more or less essential for any serious airbrush use. All good comps such as the 'Bambi' units come with reservoirs and reg/trap……these units have been, and still are, quite pricey albeit UK made items, however, bambi no do a nice amateur model which is small and silent with decent sized reservoir and comes in at about £100 or less according to supplier/online etc.
If you look online/youtube there are people putting together their own comps…..Teh Steve Jordan video is probably the best one as he makes wha tis virtually a pro tool using a fridge unit.