Trust Him when He said that He will always be with us in Matthew 28:20. I have been through those times myself and have found that a) the bible does not say we will always feel His presence and B) just because I can't feel Him doesn't mean He is not there. I find that it is when those times are over and I look back I can see that He was with me all along but I didn't know. At these times we can either trust Him and lean on His words in the bible that tell us He won't leave us orphans and that He will always be with us or let it discourage us and, maybe, turn from Him believing He left us. It is not easy at the time we can't feel Him but it is the time we learn to trust without seeing. Remember Thomas saw Jesus and believed because he saw Jesus then Jesus told Him that those who don't see Him and believe still are blessed: John 20:29 Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed are they that have not seen, and yet have believed. I know it is hard but trust Jesus and lean on Him and His words in the bible no matter what and know that if you have done as He asked, repented and believed, that you are saved and He is with you no matter what your feelings or emotions tell you. Remember feelings and emotions often get it wrong.
Hope this helps :)