It could be helpful to firstly evaluate your exercise plan and think of what parts you enjoy/don't enjoy - obviously, an exercise plan can never be ideal! But if you can put in more things you enjoy, it's easier to be motivated to do them.
There are also other things you could use to motivate yourself! There are two types of motivation: positive and negative. One may work better for you, or you could use both. An example of positive motivation would be: If I do x amount of exercise today, I'll allow myself some time to watch my favourite tv show." An example of negative motivation is: "If I don't exercise today, I'm going to feel really unhealthy." While 'negative' motivation sounds like a bad thing - it can be really useful if it works for you!
Finally, you could try different types of exercise like sports, zumba, gym, jogging, etc. Maybe even incorporate a few of these into your weekly plan if you like variety! Having a range of things we can try means that there's more chance one will stick with us and it can make it more interesting when there's variety.
I understand it can be hard to commit to a routine. If you don't like monotomy you can try different activities to keep doing exercise. For example, you can try an exercise routine plus different sports as swimming, riding bicycle, running, etc, you can join to different classes as yoga, pilates, boxing, the ones you like and enjoy. There are many different activities in which you can exercise. So if you don't like monotomy you can try something different each week or month and go back to the ones you like the most from time to time.
Start small with setting your goals. Like really, really small. You want to build your confidence with achieving small goals so that you know you can accomplish bigger challenges. For example , instead of saying that you want to exercise for 2hrs everyday, start with something that you know you can do. So maybe in the beginning your goal is to walk 2 blocks everyday. Then maybe the next week is to walk the equivalent of three blocks, and so on. You don't want to rush yourself by starting with your end goal first.
Get a couple friends or family members to try to commit to that routine with you. If they are of similar physical shape to you, it will be more fun than just exercising on your own, and this way you and your gym buddies will keep each other in check and make sure you commit to the routine