You may be tired and dizzy due to an infection. Inner ear infections can cause dizzy spells.
Tiredness and dizzy turns can also be caused by having low iron levels causing anaemia.
Because you have used laxatives for a very long time, it is likely that your bowels have become "lazy".
A healthy and well balanced diet with lots of fresh fruit and vegetables and lots of water is very important for good health. The fibre in the fruit and vegetables and the water as well as exercise (walking is fine) will help with bowel movements. Make sure that you do drink plenty of fluids - 2 litres of water a day is usually recommended, but you may need more if you sweat a lot.
Rather than taking laxatives, your doctor can prescribe for you (or you can purchases these yourself from the pharmacy), are stool softeners.
When you eat fibre, you also need fluids. The stool softeners keep the moisture in the stools so that they are not hard and do not constipate you.
You mix a sachet up with a glass of water and drink it. Follow the directions on the packet - you can take more than 1 sachet in a day depending on your constipation.
Make an appointment to see your doctor and discuss with him your tiredness and dizzy feelings as well as your bowel problems.
The doctor may decide to take a blood test to check your iron levels and Vitamin B12.
Vitamin or mineral deficiency , hypothyroid , Addison's disease are to be ruled out a stool sample to rule out parasitic infestation but it does miss it often get empirical treatment for intestinal parasites might be better,mention these to your doctor and see if it can be fixed , ovarian malignency tends to present first by gastrointestinal troubles , and many other more differential diagnoses , growth hormone deficiency and panhypopituitarism are alternate diagnoses , it could be a simple matter if diet
The more you use "outside" means to help with constipation issues, the less effective your body's abilty to eliminate, becomes.
Now, I don't know if this is your situation at all, however, your diet must be optimized for such a condition along with proper hydration and activity.
The longer you have no BM, the worse it is for you as the accumulation of toxins and harmful bacteria keeps increase and causing continious damage.
You should consider seeing your doctor, or if it takes too long for an appointment, you should go to the ER, where you will be properly be given an enema, something which could also be done at home.
My opinion is that you should get a medical evaluation first, before giving any consideration to the self-treatment, just in case
there are other underlying implications.
I hope this helps, however, my comments and suggestions are not intended to replace medical advice.
Best wishes.
Niko