Maybe play the game casually until you get the gear to solo the tower. Or just don't play a game you don't have enough time to dedicate to. Ive been a mostly solo player since alpha of destiny 1 so I get the struggle. But if you choose to play solo, you need to accept that you need to be at best, top tier in terms of gear to beat some content. We can go back and fourth and talk about difficulty settings and making content that hardens with the addition of more players but that's not in the table right now so it doesn't do you any good.