OP, thank you for asking the question. I found myself feeling this way too, recently - afraid that I'm not doing enough or that my sins are just too many to be forgiven (a lie told to us by the adversary and one we allow ourselves to entertain - even when we know it isn't true, that's the true cunning nature of the fallen one, IMO).

I'm learning quite a bit from the comments and it's a relief to know that Jesus paid the price and all that is we have to do submit to His will and believe His price wasn't paid in vain. It's my own personal belief that God knows your heart - there is no thinking, doing or explaining your way into salvation, it starts and end with Him but we must choose to be open to his spirit. At least...that's where I'm at with what I've just read in this thread.