tl;dr
belief is a gift which can only be received, it cannot be manufactured

the beauty of gods in our ancient land is you can be a devotee of whomsoever you vibe with + you don't have to stick to 1 ishta dev

one day you could be chanting shiva-tandav-strotam & another day you could be doing a jaap of Om Namo Bhagavate Vasudevaya 

I listen to main gyanand swabhavi hun when I seek to be like the Tirthankars

I have also often found peace in ek-onkar

it's about what you want to emulate from your gods on that day

the devotion gives you specific strength - you ask the gods to give you similar abilities as them

don't make harsh rules here, just vibe and spend a lot of time on bhakti - it will likely give you the capabilities you desire

it's not about material stuff, it's about emulation

the prayer to be like them

may you find more belief in you 🙏🏻