How can I become a better Muslim and consistently follow Allah’s commandments?

Although I am more than 40 years of age, I do not see much change in myself in obeying the commandment of Allah and His messenger. I have been trying to attend congregation prayer which only lasting for several weeks and then I completely abandon it though I would still pray alone and so as other ibadah. Sometimes I read Quran then I again leave the reading for a long time. In my heart I do want to be a pious slave of Allah and always imagine what kind of punishment that I would receive in the hereafter. What shall I do to strengthen my iman and consistently doing the ibadah without fail I fear I would not make myself a good Muslim in this world and in akhirah let alone a severe punishment from Allah. In my heart I do feel that I love Allah and His Rasul (SAW) but how could I claim so when I am not truly following Allah’s commandment? Please advise me and what good course of actions should I take to rectify myself.