I think you are always going to struggle as an alpha trying to trade. You can’t get the relevant skills to a high enough level to compete with the professionals.
Remember, trading is just as much a PvP activity as blowing up ships, and in the same way, you need to choose your fights carefully. Trying to take on the professionals at the 0.1 isk game in Jita is like attacking a capital ship in a Velator.
I’d suggest moving to Amarr or even Dodixie and concentrate on larger margin, slower moving goods. As noted above, watch for goods at the bottom of their cycle and buy, selling as the cycle improves. This takes time and planning.
Or join a null sec corp, check what they need and supply it - you can utilise their jump freighter services to move your goods, often at decent margin. Faction warfare hubs are good too - I used to make a fair bit supplying Vlillirier with drones and ammunition.